剑指offer47 礼物的最大价值

简单记录下动态规划中，扩充边界兼容处理边界问题
源自于题解评论中

题目：https://leetcode-cn.com/problems/li-wu-de-zui-da-jie-zhi-lcof/

class Solution {
    public int maxValue(int[][] grid) {
        int n = grid.length, m = grid[0].length;
        int[][] dp = new int[n+1][m+1];  //这里扩充边界，最外面都是0
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= m; j++) {
                dp[i][j] = Math.max(dp[i-1][j], dp[i][j-1]) + grid[i-1][j-1];
            }
        }
        return dp[n][m];
    }
}

要简洁、优雅👍