64. Minimum Path Sum

Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.

这题之前写过了（1月份..那时候还没开始发题解在这里），昨天看了dp的直播今天又写一遍。这题虽是二维dp，但思维难度不大，思路很清晰。刷刷写出来一次AC了。

    public int minPathSum(int[][] grid) {
        int row = grid.length;
        if (row == 0) return 0;
        int col = grid[0].length;
        int dp[][] = new int[row][col];
        dp[0][0] = grid[0][0];
        for (int i = 1; i < row; i++) {
            dp[i][0] = dp[i - 1][0] + grid[i][0];
        }
        for (int i = 1; i < col; i++) {
            dp[0][i] = dp[0][i - 1] + grid[0][i];
        }

        for (int i = 1; i < row; i++)
            for (int j = 1; j < col; j++) {
                dp[i][j] = Math.min(dp[i - 1][j], dp[i][j - 1]) + grid[i][j];
            }
        return dp[row - 1][col - 1];
    }