LeetCode_Minimun Path Sum

Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.

Note: You can only move either down or right at any point in time.

典型的动态规划小题!

#include <iostream>#include <vector>using namespace std;class Solution {public:    int minPathSum(vector<vector<int> > &grid) {        int rowNo = grid.size();        if(rowNo == 0){return 0;}        int colNo = grid[0].size();        if (colNo == 0){        return 0;        }        std::vector <vector<int>> dp (rowNo,std::vector<int> (colNo,0));        dp[0][0]=grid[0][0];        for(int i=1;i<rowNo;i++){        dp[i][0]=dp[i-1][0]+grid[i][0];        }        for(int j=1;j<colNo;j++){        dp[0][j]=dp[0][j-1]+grid[0][j];        }        //start dp        for(int i=1;i<rowNo;i++){        for(int j=1;j<colNo;j++){        if(dp[i-1][j]>dp[i][j-1]){        dp[i][j]=dp[i][j-1]+grid[i][j];        }        else{        dp[i][j]=dp[i-1][j]+grid[i][j];        }        }        }        return dp[rowNo-1][colNo-1];    }};