#include <vector> 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; }//初始第一一列 for(int j = 0; j < n; j++){ dp[0][j] = 1; }//初始化第一行 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]; } };