题解

Easy.

动态规划。

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