64.minPathSum

64.最小路径和

class Solution {
     
    public int minPathSum(int[][] grid) {
     
        if(grid==null||grid.length==0||grid[0].length==0){
     
            return 0;
        }
        int m=grid.length;
        int n=grid[0].length;
        int[][] dp=new int[m][n];
        dp[0][0]=grid[0][0];
        for(int i=0;i<m;i++){
     
            for(int j=0;j<n;j++){
     
                if(i==0&&j>0){
     
                    dp[i][j]=dp[i][j-1]+grid[i][j];
                }else if(j==0&&i>0){
     
                    dp[i][j]=dp[i-1][j]+grid[i][j];
                }else if(i>0&&j>0){
     
                    dp[i][j]=Math.min(dp[i-1][j],dp[i][j-1])+grid[i][j];
                }
            }
        }
        return dp[m-1][n-1];

    }
}