《leetCode》：Minimum Path Sum

题目

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.

思路

此题和前面几个题的思路一模一样。
思路：每个点到终点的最短路径等于min(右边节点的最短路径,正下方节点的短路径 );

int minPathSum(int** grid, int gridRowSize, int gridColSize) {    if(grid==NULL||gridRowSize<1||gridColSize<1){        return 0;    }    if(gridRowSize==1&&gridColSize==1){        return grid[0][0];    }    //换两个短点的变量来表示     int m=gridRowSize;    int n=gridColSize;    //开辟一段空间来保存结果    int **result=(int **)malloc(m*sizeof(int *));    if(result==NULL){        exit(EXIT_FAILURE);    }    for(int i=0;i<m;i++){        result[i]=(int *)malloc(n*sizeof(int));        if(result[i]==NULL){            exit(EXIT_FAILURE);        }        memset(result[i],0,n*sizeof(int));//初始化为零     }    result[m-1][n-1]=grid[m-1][n-1];    //最后一列       for(int i=m-2;i>=0;i--){            result[i][n-1]=result[i+1][n-1]+grid[i][n-1];    }    //最后一行      for(int i=n-2;i>=0;i--){            result[m-1][i]=result[m-1][i+1]+grid[m-1][i];    }    for(int i=m-2;i>=0;i--){        for(int j=n-2;j>=0;j--){                result[i][j]=((result[i+1][j]<=result[i][j+1])?result[i+1][j]:result[i][j+1])+grid[i][j];                //result[i][j]=min(result[i+1][j],result[i][j+1])+grid[i][j];                   }    }    return result[0][0]; }