题解 | #矩阵的最小路径和#

import java.util.*;


public class Solution {
    /**
     * 
     * @param matrix int整型二维数组 the matrix
     * @return int整型
     */
    public int minPathSum (int[][] matrix) {
        // write code here
        if (matrix == null || matrix.length < 1 || matrix[0] == null || matrix[0].length < 1) {
            return 0;
        }
        int n = matrix.length;
        int m = matrix[0].length;
        int[][] dp = new int[n][m];
        dp[0][0] = matrix[0][0];
        for (int i = 1; i < n; i++) {
            dp[i][0] = dp[i - 1][0] + matrix[i][0];
        }
        for (int j = 1; j < m; j++) {
            dp[0][j] = dp[0][j - 1] + matrix[0][j];
        }
        for (int i = 1; i < n; i++) {
            for (int j = 1; j < m; j++) {
                dp[i][j] = Math.min(dp[i - 1][j], dp[i][j - 1]) + matrix[i][j];
            }
        }
        return dp[n - 1][m - 1];
    }
}