LeetCode练习记录2017/12/10

【136】Single Number

class Solution {public:    int singleNumber(vector<int>& nums) {        int result=0;        for(int i=0;i<nums.size();i++)        {            result^=nums[i];        }        return result;    }};

【553】OPtimal Division

class Solution {public:string optimalDivision(vector<int>& nums) {string a=to_string(nums[0]);        if(nums.size()==1)            return a;        if(nums.size()==2)        {            a+="/";            a+=to_string(nums[1]);            return a;        }a += "/(";for(int i=1;i<nums.size()-1;i++){string temp = to_string(nums[i]);temp += "/";a += temp;}a += to_string(nums[nums.size() - 1]);a += ")";return a;}};

【693】Binary Number with Alternating bits

class Solution {public:bool hasAlternatingBits(int n) {bool res = true;while(n>0){int n1 = n % 2;n /= 2;int n2 = n % 2;res = n1^n2;if (!res)break;}return res;}};

【413】Arithmetic Slices

class Solution {public:int numberOfArithmeticSlices(vector<int>& A) {int flag = 1;int cha = 0xffffffff;int res = 0;for(int i=1;i<A.size();i++){if(cha!=A[i]-A[i-1]){cha = A[i] - A[i - 1];if(flag>2){res += (flag - 1)*(flag - 2) / 2;}flag = 2;}else flag++;}if (flag>2){res += (flag - 1)*(flag - 2) / 2;}return res;}};

【526】Beautiful Arrangement

class Solution {public:int countArrangement(int N) {index = N;memset(visit, 0, sizeof(int));dfs(N);return res;}int res = 0;int index;int visit[16];void dfs(int n){if(n==1){res++;return;}for(int i=1;i<=index;i++){if(visit[i]==0&&(n%i==0||i%n==0)){visit[i] = 1;dfs(n - 1);visit[i] = 0;}}}};