题解 | #走方格的方案数#

#include <iostream>
#include <vector>
using namespace std;

int main() {
    int n, m;
    cin >> n >> m;

    vector<vector<int>> dp(n+1, vector<int>(m+1, 0));
    for (int i = 0; i < n+1; i++) {
        for (int j = 0; j < m+1; j++) {
            if (i == 0 && j == 0)
                dp[i][j] = 1;
            else if (i == 0)
                dp[i][j] = dp[i][j - 1];
            else if (j == 0)
                dp[i][j] = dp[i - 1][j];
            else
                dp[i][j] = dp[i][j - 1] + dp[i - 1][j];
        }
    }

    cout << dp[n][m] << endl;
}
// 64 位输出请用 printf("%lld")