<剑指offer>javascript解法（1-65）

采用的是牛客网上的判题系统javascript(V8 6.0.0) 和 Node.js

1.二维数组的查找

function Find(target, array){    // write code here     var row = array.length;  // 行数    var col = array[0].length;  // 列数        // 从右上角开始比较    var r = 0;    var c = col-1;       while(r <=row-1 && c >= 0) { // 注意这里有等于号        if (target > array[r][c]) {            r++;        }        else if (target < array[r][c]) {            c--;        }        else {            return true;        }    }    return false;}

 

2.替换空格

function replaceSpace(str){    // write code here   return str.replace(/\s+?/g,'%20')}

 

3.从尾到头打印链表

function printListFromTailToHead(head){    // write code here    var res = [];    while(head!=null){        res.push(head.val);        head = head.next;    }    return res.reverse();}

 

4.重建二叉树

function reConstructBinaryTree(pre, vin){    // write code here   if (!pre || pre.length === 0) {        return;    }        var treeNode = {        val: pre[0]    }    for(var i = 0; i < pre.length; i++) {        if (vin[i] === pre[0]) {            treeNode.left = reConstructBinaryTree(pre.slice(1, i+1), vin.slice(0, i));            treeNode.right = reConstructBinaryTree(pre.slice(i+1),vin.slice(i+1));        }    }    return treeNode;}

 

5.用两个栈实现队列

var result=[];function push(node){    // write code here    result.push(node)}function pop(){    // write code here    return result.shift()}

 

6.旋转数组的最小数字

function minNumberInRotateArray(rotateArray){    // write code here    rotateArray.sort(function(a,b){        if(a<b){            return -1;        }        else            return 1;            })    return rotateArray[0];}

 

7.斐波那契数列（循环方法）

function Fibonacci(n){    // write code here    if(n==0||n==1){        return n;    }    var f1 = 0;    var f2 = 1;    for(var i =2;i<=n;i++){        var tmp = f1 + f2;        f1 = f2;        f2 = tmp;    }    return tmp;}

 

8.跳台阶

function jumpFloor(number){    // write code here    if(number==1){        return 1;    }    if(number==2){        return 2;    }    var f1 = 1;    var f2 = 2;    for(var i=2;i<number;i++){        var tmp = f1+ f2;        f1 = f2;        f2 = tmp;    }    return f2;}

 

9.变态跳台阶

function jumpFloorII(number){    // write code here    if(number==1){        return 1;    }    if(number==2){        return 2;    }    else        return 2*jumpFloorII(number-1);}

 

10.矩形覆盖

function rectCover(number){    // write code here    if(number<=0){        return 0;    }    if(number==1||number==2){        return number;    }           var f1 = 0;    var f2 = 1;    for(var i=1;i<=number;i++){        var tmp = f1 + f2;        f1 = f2;        f2 = tmp;    }    return f2;}

 

11.二进制中1的个数

 

function NumberOf1(n){    // write code here    var count = 0;    while(n!=0){        n = n&(n-1);        count++    }    return count;}

 

 

12.数值的整数次方

function Power(base, exponent){    // write code here    if(exponent==0){        return 1;    }    var result = 1;    if(exponent>0){        for(var i=1;i<=exponent;i++){            result *= base;        }        return result;    }    if(exponent<0){        exponent = Math.abs(exponent);         for(var i=1;i<=exponent;i++){            result *= base;        }        result = 1/result;        return result;    }}

 

13.调整数组元素顺序使奇数位于偶数之前

function reOrderArray(array){    // write code here    var result1 = [];    var result2 = [];    for(var i=0;i<array.length;i++){        if(array[i]%2==0){            result1.push(array[i]);        }        else{            result2.push(array[i]);        }     }    return result2.concat(result1);}

 

 14.链表中倒数第k个结点

function FindKthToTail(head, k){    // write code here    if(head==null||k<=0) return null;    var prev = head;    var tail = head;    for(var index=0;index<k-1;index++){        if(tail.next!=null){            tail=tail.next;        }else{            return null;        }            }        while(tail.next!=null){        prev=prev.next;        tail=tail.next;    }    return prev;}module.exports = {    FindKthToTail : FindKthToTail};

 

15.反转链表

function ReverseList(pHead){    // write code here    if(pHead==null||pHead.next==null) return pHead;    var prev=null;    var next=null;    while(pHead!=null){        next=pHead.next;        pHead.next=prev;        prev=pHead;        pHead=next;    }    return prev;}module.exports = {    ReverseList : ReverseList};

 

16.合并两个排序的链表

function ListNode(x){    this.val = x;    this.next = null;}function Merge(pHead1, pHead2){    // write code here    var head=new ListNode(0);    var pHead=head;    while(pHead1!=null && pHead2!=null){        if(pHead1.val>=pHead2.val){            head.next=pHead2;            pHead2=pHead2.next;        }else{            head.next=pHead1;            pHead1=pHead1.next;        }        head=head.next;    }    if(pHead1!=null){        head.next=pHead1;    }    if(pHead2!=null){        head.next=pHead2;    }    return pHead.next;}module.exports = {    Merge : Merge};

 

17.树的子结构

 function TreeNode(x) {    this.val = x;    this.left = null;    this.right = null;}function isSubtree(pRoot1,pRoot2){    if (pRoot2 == null) return true;//pRoot2为null，表示子树已经遍历完    if (pRoot1 == null) return false;    if(pRoot1.val==pRoot2.val){        return isSubtree(pRoot1.left,pRoot2.left) && isSubtree(pRoot1.right,pRoot2.right);    }else{        return false;    }}function HasSubtree(pRoot1, pRoot2){    // write code here    if(pRoot1==null||pRoot2==null) return false;       return isSubtree(pRoot1,pRoot2)||HasSubtree(pRoot1.left,pRoot2)||HasSubtree(pRoot1.right,pRoot2);}module.exports = {    HasSubtree : HasSubtree};

 

18.二叉树的镜像

function Mirror(root){    // write code here    if(root==null) return null;    //首先先将左右节点互换    var  tmp = root.left;    root.left=root.right;    root.right=tmp;    //递归    Mirror(root.left);    Mirror(root.right)}module.exports = {    Mirror : Mirror};

 

19.顺时针打印矩阵

function printMatrix(matrix){    // write code here    if(matrix==null || matrix.length==0) return;    var rows = matrix.length;    var cols = matrix[0].length;    var start=0;    var result=[];    while(cols>start*2 && rows>start*2){        //x，y方向边界值        var endX = cols-1-start;        var endY = rows-1-start;        //左到右        for(var i = start;i<=endX;i++){            result.push(matrix[start][i])        }        //上到下        if(start<endY){            for(var i = start+1;i<=endY;i++){                result.push(matrix[i][endX])            }        }                //右到左        if(start<endX && start<endY){            for(var i = endX-1;i>=start;i--){                result.push(matrix[endY][i])            }        }        //下到上        if(start<endX && start<endY-1){            for(var i = endY-1;i>=start+1;i--){                result.push(matrix[i][start])            }        }        start++    }    return result;}module.exports = {    printMatrix : printMatrix};

 

20.包含min函数的栈

var result=[]function push(node){    // write code here    return result.push(node)}function pop(){    // write code here    return result.pop()}function top(){    // write code here    return result.length>0?result[result.length-1]:null;}function min(){    // write code here    if(result.length==0||result==null) return;    var min=result[0];    result.map(function(a){        if(a<min){            min=a;        }    })    return min;}

 

21.栈的压入，弹出序列

function IsPopOrder(pushV, popV){    // write code here    var tmp=[];    for(var i=0,j=0;i<pushV.length;i++){        tmp.push(pushV[i]);        while(tmp.length&&tmp[tmp.length-1]==popV[j]){            tmp.pop();            j++;        }    }    return tmp.length==0;}

 

22.从上往下打印二叉树

function PrintFromTopToBottom(root){    // write code here     if(root==null) return [];    var result=[];        result.push(root.val);    function travel(root){        if(root.left==null && root.right==null) return;        if(root.left!=null) result.push(root.left.val)        if(root.right!=null) result.push(root.right.val)        if(root.left!=null) travel(root.left);        if(root.right!=null) travel(root.right);    }    travel(root);    return result;}

 

23.二叉树的搜索和后续遍历

function VerifySquenceOfBST(sequence){    // write code here    if(sequence.length<=0) return;    return test(sequence,0,sequence.length-1)}function test(sequence,start,end){    if(start>=end) return true;    var i=end-1;    while(i>=start && sequence[i]>sequence[end]){        i--;    }    for(var j=i;j>=start;j--){        if(sequence[j]>sequence[end]){            return false;        }    }    return test(sequence,start,i)&&test(sequence,i+1,end-1)}

 

24.二叉树中和为某一值的路径

function FindPath(root, expectNumber){    // write code here    var result=[];    if(root==null) return result;    dfs(root,0,[]);    function dfs(root,current,path){        current+=root.val;        path.push(root.val)        if(current==expectNumber && root.left==null && root.right ==null){            result.push(path.slice(0))        }        if(root.left!=null){            dfs(root.left,current,path)        }        if(root.right!=null){            dfs(root.right,current,path)        }        path.pop()    }    return result;}

 

25.复杂链表的复制

function RandomListNode(x){    this.label = x;    this.next = null;    this.random = null;}function Clone(pHead){    // write code here        if (!pHead) {        return null;    }    // 复制头结点    var node = new RandomListNode(pHead.label);    node.random = pHead.random;    // 递归其他节点    node.next = Clone(pHead.next);    return node;}

 

26.二叉搜索树和双向链表

function Convert(pRootOfTree){    // write code here    if(pRootOfTree==null){        return null;    }    var lastNode=null;    lastNode=convertNode(pRootOfTree,lastNode);    var head=lastNode;    while(head && head.left){//循环到头部        head=head.left;    }    return head;}function convertNode(root,lastNode){    if(root==null) return;    if(root.left){//左子树        lastNode=convertNode(root.left,lastNode)    }    root.left=lastNode;    if(lastNode){        lastNode.right=root;    }    lastNode=root;    if(root.right){//右子树        lastNode=convertNode(root.right,lastNode)    }    return lastNode;}

 

27.字符串的排列

function Permutation(str){    // write code here    var result=[];    if(str.length<=0){        return [];    }    var sortTemp='';    var arr = str.split('');    result=sortString(arr,sortTemp,[]);    return result}function sortString(arr,sortTemp,result){    if(arr.length==0){        result.push(sortTemp)    }else{        var isRepeat={};        for(var i=0;i<arr.length;i++){            if(!isRepeat[arr[i]]){                var temp=arr.splice(i,1)[0];//取出第一个字符                sortTemp+=temp;                sortString(arr,sortTemp,result);                arr.splice(i,0,temp);//补全                sortTemp=sortTemp.slice(0,sortTemp.length-1)//清空                isRepeat[temp]=true;            }        }    }    return result;}

 

28.数组中出现次数超过一半的数字

function MoreThanHalfNum_Solution(numbers){    // write code here       var obj={};    var len = numbers.length;    numbers.map(function(num){        if(obj[num]){            obj[num]++        }else{            obj[num]=1;        }    })    for (var i in obj){        if(obj[i]>Math.floor(len/2)) return i    }    return 0;}

 

29.最小的k个数

function GetLeastNumbers_Solution(input, k){    // write code here    if(input==null){        return null;    }    if(input.length<k){        return [];    }    input.sort(function(a,b){        return a>b;    })    var result = [];    for(var i=0;i<k;i++){        result.push(input[i]);    }    return result;}

 

30.连续子数组的最大和

function FindGreatestSumOfSubArray(array){    // write code here    if (array.length === 0) return 0;  var max = array[0];  var temp = array[0];  for (var i = 1; i < array.length; i++) {    temp = temp > 0 ? temp + array[i] : array[i];    max = max > temp ? max : temp;  }  return max；}

 

31.从1到n数字中1出现的次数

function NumberOf1Between1AndN_Solution(n){    // write code here     if(n<0){        return 0;    }    var count=0;  for(var i = 1;i<=n;i++){    var number = i;    while(number>0){        if(number%10==1){            count++;        }        number = Math.floor(number/10);       // console.log(number);    }  }       return count;    }

 

32.把数组排成最小的数

function PrintMinNumber(numbers){    // write code here    if (!numbers.length)        return "";    min=Number.POSITIVE_INFINITY;    return Sort(numbers, 0);} function Sort(numbers, index) {    for (var i = index, l = numbers.length; i < l; ++i) {        var temp = numbers[i];        numbers[i] = numbers[index];        numbers[index] = temp;         if (index != numbers.length - 1)            Sort(numbers, index + 1, min);        else {            var tempS = numbers.join("").toString();            if (min > tempS) {                min = tempS;            }        }         temp = numbers[i];        numbers[i] = numbers[index];        numbers[index] = temp;    }    return min;}

 

33.丑数

function GetUglyNumber_Solution(index){    // write code here    var res = [],        multiply2 = 0,        multiply3 = 0,        multiply5 = 0,        nextIndex = 1         res[0] = 1         if(index <= 0)        return 0             while(nextIndex < index)    {        res[nextIndex] = min( res[multiply2] * 2, res[multiply3] * 3, res[multiply5] * 5 )                 while( res[multiply2] * 2 <= res[nextIndex] )        {            ++multiply2        }                 while( res[multiply3] * 3 <= res[nextIndex] )        {            ++multiply3        }                 while( res[multiply5] * 5 <= res[nextIndex] )        {            ++multiply5        }                 ++nextIndex    }         return res[--nextIndex]      } function min(a,b,c){    var min         min = (a < b) ? a : b    min = (min < c) ? min : c         return min}

 

34.第一个只出现一次的字符

function FirstNotRepeatingChar(str){    // write code here    if(!str){        return -1;    }    var flag = {};    var len = str.length;    for(var i = 0;i<len;i++){        if(flag[str[i]]){            if(flag[str[i]]>2){                continue;            }else{                flag[str[i]]++;            }        }else{            flag[str[i]] = 1;        }    }    for(var i = 0;i<len;i++){        if(flag[str[i]] == 1){            return i;        }    }}module.exports = {    FirstNotRepeatingChar : FirstNotRepeatingChar};

 

35.数组中的逆序对

function InversePairs(data){    // write code here      if(!data || data.length < 2){        return 0;    }    var copy = data.concat(), count = 0;    count = MergeSort(data, copy, 0, data.length-1);    return count % 1000000007;}function MergeSort(data, copy, start, end){    if(end === start){        return 0;    }    var len = Math.floor((end - start) / 2);    var left = MergeSort(copy, data, start, start+len);    var right = MergeSort(copy, data, start+len+1, end);    var count = 0;    var p = start+len, q = end, copyIndex = end;    while(p >= start && q >= start+len+1){        if(data[p] > data[q]){            count += q - start - len;            copy[copyIndex--] = data[p--];        }else{            copy[copyIndex--] = data[q--];        }    }    while(p >= start){        copy[copyIndex--] = data[p--];    }    while(q >= (start+len+1)){        copy[copyIndex--] = data[q--];    }    return left + right + count;}module.exports = {    InversePairs : InversePairs};

 

36.两个链表的第一个公共结点

function ListNode(x){    this.val = x;    this.next = null;}function FindFirstCommonNode(pHead1, pHead2){    // write code here    var arr1 = [],        arr2 = [],        p1 = pHead1,        p2 = pHead2,        index = -1;    while(p1){        arr1.push(p1.val);        p1 = p1.next;    }    while(p2){        arr2.push(p2.val);        p2 = p2.next;    }         for(var i = 0 ; i < arr1.length; i ++){        var arr = arr1.slice(i);        var str1 = arr.join("-");        var str2 = arr2.join("-");                 if(str2.indexOf(str1) > -1){            index = i;            break;        }    }         if(index < 0){return null;}    var p = pHead1;    while(index > 0){        p = p.next;        index --;    }    return p;}module.exports = {    FindFirstCommonNode : FindFirstCommonNode};

 

37.数字在排序数组中出现的次数

function GetNumberOfK(data, k){    // write code here    if (data == null) {        return 0;    }     var leftIndex = leftIndexOfKeyInSortedArray(data, k);    if (leftIndex == -1) {        return 0;    }    var rightIndex = rightIndexOfKeyInSortedArray(data, k);    return rightIndex - leftIndex + 1;}function leftIndexOfKeyInSortedArray(data, key) {    if (data == null) {        return -1;    }    var low = 0;    var high = data.length - 1;    var ret = -1;    while (low <= high) {        var mid = Math.floor((low + high) / 2);        if (data[mid] == key) {            ret = mid;            high = mid - 1;        } else if (data[mid] > key) {            high = mid - 1;        } else {            low = mid + 1;        }    }    return ret;} function rightIndexOfKeyInSortedArray(data, key) {        if (data == null) {            return -1;        }        var low = 0;        var high =data.length - 1;        var ret = -1;        while (low <= high) {            var mid = Math.floor((low + high) / 2);            if (data[mid] == key) {                ret = mid;                low = mid + 1;            } else if (data[mid] > key) {                high = mid - 1;            } else {                low = mid + 1;            }        }        return ret;}module.exports = {    GetNumberOfK : GetNumberOfK};

 

38.二叉树的深度

function TreeDepth(pRoot){    // write code here    if(pRoot == null){        return 0;    }    var left = TreeDepth(pRoot.left)+1;    var right = TreeDepth(pRoot.right)+1;    return Math.max(left, right);    }

 

39.平衡二叉树

var isBalanced = true; function isBalancedCore(pRoot) {  if (!pRoot) {    return 0;  }  var leftCount = 0;  var rightCount = 0;  if (pRoot.left) {    leftCount = isBalancedCore(pRoot.left);  }  if (pRoot.right) {    rightCount = isBalancedCore(pRoot.right);  }  if (Math.abs(leftCount - rightCount) > 1) {    isBalanced = false;  }  return leftCount > rightCount ? leftCount + 1 : rightCount + 1;} function IsBalanced_Solution(pRoot){    // write code here    if (!pRoot) {      return true;    }    isBalancedCore(pRoot);    var ret = isBalanced;    isBalanced = true;    return ret;}module.exports = {    IsBalanced_Solution : IsBalanced_Solution};

 

40.数组中只出现一次的数字

function FindNumsAppearOnce(array){    // write code here    // return list, 比如[a,b]，其中ab是出现一次的两个数字    var len = array.length,        num1,        num2,        resXOR = 0,        indexOf1         if( len < 2 )        return    for(var i=0; i<len; i++)    {        resXOR ^= array[i]    }         indexOf1 = find1( resXOR )         for(var j=0; j<len; j++)    {        if(IsBit1( array[j], indexOf1 ))        {            num1 ^= array[j]        } else {            num2 ^= array[j]        }    }         return [ num1, num2 ]} function find1(bit){    var index = 0         while((bit & 1) == 0)    {        bit = bit >> 1        index++    }         return index} function IsBit1(bit, index){    var num = bit >> index         return (num & 1)}module.exports = {    FindNumsAppearOnce : FindNumsAppearOnce};

 

41.和为s的连续正整数序列

function FindContinuousSequence(sum){    // write code here     var low=1,high=2;    array=[];    while(high>low){        var cur=(high+low)*(high-low+1)/2;        if(cur<sum){            high++;        }        if(cur===sum){            var arr=[];            for(var i=low;i<=high;i++){                arr.push(i);            }            array.push(arr);            low++;        }        if(cur>sum){            low++;        }    }    return array;}module.exports = {    FindContinuousSequence : FindContinuousSequence};

 

41.和为s的两个数字

function FindNumbersWithSum(array, sum){    // write code here    var len = array.length,        small = 0,        big = len - 1,        curSum = 0,        curMul,        mul = 9007199254740991,        res = []         if(len < 2)        return res             while(small < big)    {         curSum = array[small] + array[big]         if(curSum == sum)        {            curMul = array[small] * array[big]            if( curMul < mul )            {                mul = curMul                res.push( array[small], array[big] )            }             small ++         }         if(curSum < sum)        {            small++        } else if(curSum > sum)        {            big --        }    }         return res}module.exports = {    FindNumbersWithSum : FindNumbersWithSum};

 

42.左旋转字符串

function LeftRotateString(str, n){    // write code here    if(!str||n<0) return "";         var strArr = str.split(""),        len = strArr.length;         if(n>len) return "";         var front = strArr.slice(0, n).reverse(),        behind = strArr.slice(n, len).reverse(),        newArr = front.concat(behind);        return newArr.reverse().join("");     }module.exports = {    LeftRotateString : LeftRotateString};

 

43.翻转单词顺序列

function ReverseSentence(str){    // write code here    if(!str||!str.trim()) return str;    var strArr = str.split(" "), //获取单词数组        len = strArr.length;     var start = 0,        end = len - 1,        temp;    while (start < end) {        temp = strArr[start];        strArr[start] = strArr[end];        strArr[end] = temp;        ++start;        --end;    }    return strArr.join(" ").trim();}module.exports = {    ReverseSentence : ReverseSentence};

 

44.扑克牌顺子

function IsContinuous(numbers){    // write code here     if (numbers.length==0) return false;     //先对数组进行排序    numbers.sort(function(a, b) {        return a - b;    });     var numberOfZero = 0, //0的个数        numberOfGap = 0; //缺的个数    var len = numbers.length;    for (var i = 0; i < len && (numbers[i] === 0); ++i) {        ++numberOfZero;    }     var small = numberOfZero,        big = small + 1;    while (big < len) {        if (numbers[small] === numbers[big]) return false;        numberOfGap += numbers[big] - numbers[small] - 1;        small = big;        ++big;    }    return numberOfGap <= numberOfZero ? true : false;}module.exports = {    IsContinuous : IsContinuous};

 

45.孩子们的游戏

function LastRemaining_Solution(n, m){    // write code here    if(n === 0) {        return -1;    }    if(n === 1) {        return 0;    }    return (LastRemaining_Solution(n-1, m)+m) % n;}module.exports = {    LastRemaining_Solution : LastRemaining_Solution};

 

46.求1+2+3+...+n

function Sum_Solution(n){    // write code here     // write code here    if(n==1){        return 1;    }else{        return n+Sum_Solution(n-1);    }}

 

47.不用加减法乘除做加法

function Add(num1, num2){    // write code here     var sum = 0, tmp;    do{        sum = num1^num2;        tmp = num1&num2;        num1 = tmp << 1;        num2 = sum;    }while(tmp != 0);    return sum;}

 

48.把字符串转化为整数

function StrToInt(str){    // write code here    if(/[a-zA-Z]/.test(str)){        return 0;    }    var reg = /([\+|\-]?\d+)/;    if(reg.test(str)){        str = str.replace(reg, "$1");        return str;    }else{        return 0;    }}module.exports = {    StrToInt : StrToInt};

 

49.数组中重复的数字

function duplicate(numbers, duplication){    // write code here    //这里要特别注意~找到任意重复的一个值并赋值到duplication[0]    //函数返回True/False    if(numbers==null) return false;    if(numbers.length==1) return false;    for(var i=0;i<numbers.length;i++){        if(numbers.indexOf(numbers[i]) != numbers.lastIndexOf(numbers[i])){            duplication[0]=numbers[i];            return true;        }    }    return false;    // write code here    //这里要特别注意~找到任意重复的一个值并赋值到duplication[0]    //函数返回True/False}module.exports = {    duplicate : duplicate};

 

50.构建乘积数组

function multiply(array){    // write code here     var B=[];    B[0]=1;    B[1]=array[0];    for(var i=2;i<array.length;i++){        B[i]=B[i-1]*array[i-1];    }    var sum=1;    for(var i=array.length-2;i>=0;i--){        sum=sum*array[i+1];        B[i]=B[i]*sum;    }    return B;}module.exports = {    multiply : multiply};

 

51.正则表达式匹配

//s, pattern都是字符串function match(s, pattern){    // write code here     var patt=new RegExp('^'+pattern+'$');  return   patt.test(s);}module.exports = {    match : match};

 

52.表示数值的字符串

//s字符串function isNumeric(s){    // write code here    var reg = !isNaN(Number(s));    return reg}module.exports = {    isNumeric : isNumeric};

 

53.字符流中第一个不重复的字符

//Init module if you needfunction Init(){    // write code here    global.result = [];    return global.result}//Insert one char from stringstreamfunction Insert(ch){    // write code here    if(result[ch]){        result[ch]++    } else {        result[ch] = 1;    }}//return the first appearence once char in current stringstreamfunction FirstAppearingOnce(){    // write code here    for(var i in result){        if(result[i] === 1){            return i;        };    };    return '#';}module.exports = {    Init : Init,    Insert : Insert,    FirstAppearingOnce: FirstAppearingOnce};

 

54.链表中环的入口结点

function EntryNodeOfLoop(pHead){    // write code here    var cur =pHead,obj={},lt;    while(cur!=null){        lt=cur.val;        if(!obj[lt]){            obj[lt]=1;            cur=cur.next;        }else{            return cur;        }    }}module.exports = {    EntryNodeOfLoop : EntryNodeOfLoop};

 

55.删除链表中重复的结点

function deleteDuplication(pHead){    // write code here    if(pHead === null) return null;    if(pHead !== null && pHead.next === null) return pHead;          var first = {        val: -1,        next: pHead    }        cur = pHead,        prev = first;          first.next = pHead;    while(cur !== null && cur.next !== null){        if(cur.val === cur.next.val){            var val = cur.val;            while(cur !== null && cur.val === val){                cur = cur.next;                prev.next = cur;            };        } else {            prev = cur;            cur = cur.next;        };    };    return first.next;}module.exports = {    deleteDuplication : deleteDuplication};

 

56.二叉树的下一个结点

function GetNext(pNode){    // write code here提示数组非法越界 是因为代码有中文状态下的    if(pNode==null){        return null;    }    //分两种情况：1  节点有孩子存在，则设置一个指针从该节点的右孩子出发，一直沿着指向左节点的指针 找到叶子结点即为下一个节点         if(pNode.right!=null){        var p=pNode.right;        while(p.left!=null){            p=p.left;        }        return p;    }    //2 该节点是父亲节点的左节点  没有右子树  则找第一个当前节点是父亲节点坐孩子的节点    while(pNode.next!=null){        if(pNode==pNode.next.left){//当前节点是父节点的第一个左节点并且该节点没有右子树            return pNode.next;        }        pNode=pNode.next;    }}module.exports = {    GetNext : GetNext};

 

57.对称的二叉树

function isSymmetrical(pRoot){    // write code here    //对称二叉树  首先根节点以及其左右子树，左子树的左子树和右子树的右子树    //左子树的右子树和右子树的左子树相同即可  采用递归法         if(pRoot==null){        return true;    }    return comRoot(pRoot.left,pRoot.right);     } function comRoot(left,right){    if(left==null&&right==null){        return true;    }    if(left!=null&&right!=null){        if(left.val==right.val){            return comRoot(left.left,right.right)&&comRoot(left.right,right.left);        }    }}module.exports = {    isSymmetrical : isSymmetrical};

 

58.按之字型打印二叉树

function Print(pRoot){    var result=[];    // write code here    if(pRoot==null){        return result;    }    var queue=[];    var nextLevel=0;    queue.push(pRoot);    var toBePrinted=1;    var level=0;    var arr=[];    while(queue.length){        var temp=queue.shift();        toBePrinted--;        arr.push(temp.val);        if(temp.left){               queue.push(temp.left);            nextLevel++;        }        if(temp.right){            queue.push(temp.right);            nextLevel++;        }        if(toBePrinted==0){            toBePrinted=nextLevel;            nextLevel=0;            level++;            if(level%2==0){                arr.reverse();            }            result.push(arr);            arr = [];        }             }    return result;                }

 

59.把二叉树打印成多行

function Print(pRoot){    // write code here    var res=[]    if(!pRoot)return res    var q=[]    q.push(pRoot)          while(q.length!=0){        var l=0        var h=q.length        var arr=[]        while(l++<h){            var t=q.shift()                          arr.push(t.val)            if(t.left)q.push(t.left)            if(t.right)q.push(t.right)        }        res.push(arr)    }    return res}

 

60.序列化二叉树

function TreeNode(x) {    this.val = x;    this.left = null;    this.right = null;}var arr = [];function Serialize(pRoot){    // write code here    if(pRoot==null){        arr.push('a');    }else{        arr.push(pRoot.val);        Serialize(pRoot.left);        Serialize(pRoot.right);    }       }function Deserialize(s){    // write code here    var node = null;    if(arr.length<1){        return null;    }    var number = arr.shift();    if(typeof number == 'number'){        node = new TreeNode(number);        node.left = Deserialize(arr);        node.right = Deserialize(arr);     }    return node;}

 

61.二叉搜索树的第k个结点

function KthNode(pRoot, k){    // write code here    var arr=[];    if(pRoot===null||k<1){        return null;    }    function midInorder(root){        if(root.left!==null){             midInorder(root.left);        }        arr.push(root);        if(root.right!==null){            midInorder(root.right);        }    }    midInorder(pRoot);    return arr[k-1];}

 

62.数据流中的中位数

var arr=[];function Insert(num){   arr.push(num);   arr.sort();}function GetMedian(){   /*if(arr==null){        return 0；    }*/    var len=arr.length;    if(len==0){        return 0;    }    if(len%2==1){        return arr[Math.floor(len/2)];    }    if(len%2==0){        //var a=Math.floor(len/2);       // var b=Math.ceil(len/2);        //return (arr[a]+arr[b])/2;        return (arr[len/2]+arr[len/2-1])/2;    }     }

 

63.滑动窗口的最大值

function maxInWindows(num, size){    // write code here    var q=[];    var max=-1;    var v=[];    var i=0;    if(size>num.length||size<=0) return v;    while(size--){        q.push(num[i]);        if(num[i]>max) max=num[i];        i++;    }    v.push(max);    while(i<num.length){        var m=q.shift();        if(m==max){            max=getMax(q);        }        q.push(num[i]);        if(num[i]>max) max=num[i];        v.push(max);        i++;    }    return v;}function getMax(q){    var max=-1;    for(var i=0;i<q.length;i++){        if(q[i]>max){            max=q[i];        }    }    return max;}

 

64.矩阵中的路径

function hasPathCore(matrix, rows, cols, row, col, path, pathIndex, visited) {  var hasPath = false;  if (row < rows && col < cols && row >= 0 && col >= 0 && visited[row][col] === false) {    if (matrix[row * cols + col] === path[pathIndex]) {      visited[row][col] = true;      if (pathIndex === path.length - 1) {        hasPath = true;      } else {        hasPath = hasPathCore(matrix, rows, cols, row - 1, col, path, pathIndex + 1, visited) ||                  hasPathCore(matrix, rows, cols, row + 1, col, path, pathIndex + 1, visited) ||                  hasPathCore(matrix, rows, cols, row, col - 1, path, pathIndex + 1, visited) ||                  hasPathCore(matrix, rows, cols, row, col + 1, path, pathIndex + 1, visited);                 if (!hasPath) {          visited[row][col] = false;        }      }    }  }  return hasPath;} function hasPath(matrix, rows, cols, path){    // write code here    if (path.length <= 0) {      return true;    }    var visited = [];    var temp = [];    var i, j;    for (i = 0; i < rows; i++) {      temp = [];      for (j = 0; j < cols; j++) {        temp.push(false);      }      visited.push(temp);    }    for (i = 0; i < rows; i++) {      for (j = 0; j < cols; j++) {        if (hasPathCore(matrix, rows, cols, i, j, path, 0, visited)) {          return true;        }      }    }    return false;}module.exports = {    hasPath : hasPath};

 

65.机器人的运动范围

 function movingCount(threshold, rows, cols){    // write code here    var count=0;    if(threshold<1||rows<1||cols<1){        return count;    }    var visited=[];    for(var i=0; i<rows; i++){        visited[i]=[];        for(var j=0; j<cols; j++){            visited[i][j]=false;        }    }    count = movingCountSum(threshold,0,0,rows,cols,visited);    return count;}function movingCountSum(threshold,m,n,rows,cols,visited){    var count = 0;    if(m>=0&&m<rows&&n>=0&&n<cols&&!visited[m][n]&&getSum(m,n)<=threshold){        visited[m][n]=true;        count = 1+movingCountSum(threshold,m,n-1,rows,cols,visited)+                movingCountSum(threshold,m,n+1,rows,cols,visited)+                movingCountSum(threshold,m-1,n,rows,cols,visited)+                movingCountSum(threshold,m+1,n,rows,cols,visited);    }    return count;}function getSum(m,n){    var str = [].concat(m,n).join('');    var sum=0;    for(var i=0; i<str.length; i++){        sum+=Number(str[i]);    }    return sum;} module.exports = {    movingCount : movingCount};