[LeetCode] 64. Minimum Path Sum

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