LeetCode64 Minimum Path Sum

题目：

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.

Note: You can only move either down or right at any point in time.（Medium）

分析：

矩阵型动态规划，dp[i][j]表示到达i,j位置的。。。。

所以本题中dp[i][j]表示到达grid[i][j]的最小和。dp[i][j] = dp[i -1][j] + dp[i][j - 1];

代码：

class Solution {
public:
    int minPathSum(vector<vector<int>>& grid) {
        int dp[grid.size()][grid[0].size()];
        dp[0][0] = grid[0][0];
        for (int i = 1; i < grid.size(); ++i) {
            dp[i][0] = dp[i - 1][0] + grid[i][0];
        }
        for (int i = 1; i < grid[0].size(); ++i) {
            dp[0][i] = dp[0][i - 1] + grid[0][i];
        }
        for (int i = 1; i < grid.size(); ++i) {
            for (int j = 1; j < grid[0].size(); ++j) {
                dp[i][j] = min(dp[i - 1][j], dp[i][j - 1]) + grid[i][j];
            }
        }
        return dp[grid.size() - 1][grid[0].size() - 1];
    }
};