LeetCode 2015.7.27 64,62,59,466,48,53,113,16

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LeetCode 2015.7.27 64,62,59,466,48,53,113,1664 Minimum Path Sumclass Solution {public:    int minPathSum(vector< vector<int> >& grid) {        int row = grid.size(), col = grid[0].size();        vector< vector<int> > f;        f.resize(row);        for(int i=0;i<row;i++)        {            for(int j=0;j<col;j++)            {                int up=INT_MAX,left=INT_MAX,tmp;                if (i-1>=0) up = f[i-1][j];                if (j-1>=0) left = f[i][j-1];                if (i==0 && j==0) tmp=0;                else tmp =min(up,left);                f[i].push_back(tmp+grid[i][j]);            }        }        return f[row-1][col-1];    }};62 Unique Paths1.class Solution {public:    int uniquePaths(int m, int n) {        int f[m+5][n+5];        for(int i=0;i<=m;i++)            f[i][0] = 0;        for(int i=0;i<=n;i++)            f[0][i] = 0;        f[0][1] = 1;        for(int i=1;i<=m;i++)            for(int j=1;j<=n;j++)                f[i][j] = f[i-1][j] + f[i][j-1];        return f[m][n];    }};2. 初始化二维vectorvector<vector<int> > v(m + 1, vector<int>(n + 1, 0));初始化一维vectorvector<int> x(m+1,0);59 Spiral Matrix IIclass Solution {public:    vector< vector<int> > generateMatrix(int n) {        vector< vector<int> > f(n+2, vector<int>(n+2,0));        for(int i=0;i<=n+1;i++)        {            f[0][i] = -1;            f[n+1][i] = -1;            f[i][0] = -1;            f[i][n+1] = -1;        }        int dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};        int dir = 0, cnt = 0, total = n*n, x=1, y=0;        while (cnt != total)        {            while (f[x + dx[dir % 4]][y + dy[dir % 4]]==0)            {                x += dx[dir % 4];                y += dy[dir % 4];                cnt++;                f[x][y]=cnt;            }            dir++;        }        vector< vector<int> > ans(n, vector<int> (n));        for(int i=0;i<n;i++)        {            for(int j=0;j<n;j++)            {                ans[i][j]=f[i+1][j+1];            }        }        return ans;    }};46 Permutations1.class Solution {public:    vector<bool> flag;    vector< vector<int> > ans;    vector<int> per;    vector< vector<int> > permute(vector<int>& nums) {        flag.resize(nums.size());        per.resize(nums.size());        ans.clear();        for(int i=0;i<flag.size();i++)        {            flag[i]=true;            per[i]=0;        }        depthSearch(0,nums.size(),nums);        return ans;    }    void depthSearch(int k,int n,vector<int> nums) {        if (k==n)        {            ans.push_back(per);            return;        }        for(int i=0;i<n;i++)            if (flag[i])            {                flag[i]=false;                per[k]=nums[i];                depthSearch(k+1,n,nums);                flag[i]=true;            }        return;    }};2. next_permutationclass Solution {public:    vector< vector<int> > permute(vector<int>& nums) {        sort(nums.begin(),nums.end());        vector< vector<int> > ans;        ans.push_back(nums);        while (next_permutation(nums.begin(),nums.end()))            ans.push_back(nums);        return ans;    }};48 Rotate Image1.class Solution {public:    void rotate(vector< vector<int> >& matrix) {        int n = matrix.size();        int f[n][n];        for(int i=0;i<n;i++)        {            for(int j=0;j<n;j++)            {                f[j][n-i-1]=matrix[i][j];            }        }        for(int i=0;i<n;i++)        {            for(int j=0;j<n;j++)                matrix[i][j]=f[i][j];        }    }};2.搜的思路class Solution {public:    void rotate(vector< vector<int> >& matrix) {        int n=matrix.size()-1;        int m=n/2;        for(int i=0;i<=n;i++)            for(int j=0;j<=i;j++)            {                int tmp = matrix[i][j];                matrix[i][j]=matrix[j][i];                matrix[j][i]=tmp;            }        for(int i=0;i<=n;i++)            for(int j=0;j<=m;j++)            {                int tmp = matrix[i][j];                matrix[i][j] = matrix[i][n-j];                matrix[i][n-j]=tmp;            }    }};53 Maximum Subarray1.class Solution {public:    int maxSubArray(vector<int>& nums) {        int ans,n=nums.size();        int f[n];        if (nums.size()==0) return 0;        f[0]=nums[0];        ans=nums[0];        for(int i=1;i<n;i++)        {            f[i]=max(nums[i],f[i-1]+nums[i]);            if (f[i]>ans) ans =f[i];        }        return ans;    }};113 Path Sum IIclass Solution {public:    vector< vector<int> > ans;    vector<int> route;    vector< vector<int> > pathSum(TreeNode* root, int sum) {        route.clear();        if (root==NULL) return ans;        depthSearch(root,0,sum);        return ans;    }    void depthSearch(TreeNode* root, int tmp, int sum)    {        route.push_back(root->val);        tmp +=root->val;        if (root->left!=NULL) depthSearch(root->left,tmp,sum);        if (root->right!=NULL) depthSearch(root->right,tmp,sum);        if (root->left==NULL && root->right==NULL & tmp==sum)            ans.push_back(route);        route.pop_back();        tmp -=root->val;        return ;    }};16 3Sum Closestclass Solution {public:    int threeSumClosest(vector<int>& nums, int target) {        sort(nums.begin(),nums.end());        int closest = nums[0] + nums[1] + nums[2];        for(int i=0;i<nums.size()-2;i++)        {            if (i>0 & nums[i]==nums[i-1])                continue;            int l = i+1,r=nums.size()-1;            while (l<r)            {                int tmp = nums[i]+nums[l]+nums[r];                if (abs(tmp-target)<abs(closest-target))                    closest = tmp;                if (tmp==target)                    return target;                else                    if (tmp>target)                        r--;                    else                        l++;            }        }        return closest;    }};
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