原题链接：Leetcode 64. 最小路径和

二维数据

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

一维数组，空间优化：

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