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) {
        //思路：动态规划算法
        int row = matrix.length;
        int col = matrix[0].length;
        int[][] dp = new int[row][col];
        dp[0][0] = matrix[0][0];
        //第一列只能从上往下一次叠加
        for (int i = 1; i < row; i++) {
            dp[i][0] = matrix[i][0] + dp[i-1][0];
        }
        //第一行只能从左往右
        for (int i = 1; i < col; i++) {
            dp[0][i] = matrix[0][i] + dp[0][i-1];
        }
        //其余依次遍历
        for (int i = 1; i < row; i++) {
            for (int j = 1; j < col; j++) {
                dp[i][j] = matrix[i][j] + Math.min(dp[i-1][j], dp[i][j-1]);
            }
        }
        return dp[row-1][col-1];
    }
}