题解 | 二维斐波那契数列

#include <iostream>
#include<vector>
using namespace std;
int Fibonacci_sequence(int n,int m){
    const int mod=1e9+7;
    vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
    for (int i = 1; i <= n; i++) {
        dp[i][1] = 1;
    }
    for (int j = 1; j <= m; j++) {
        dp[1][j] = 1;
    }
    for (int i = 2; i <= n; i++) {
        for (int j = 2; j <= m; j++) {
            dp[i][j] = (dp[i - 1][j] + dp[i][j - 1])%mod ;
        }
    }
    return dp[n][m];
    
}
int main() {
    int n,m;
    cin>>n>>m;
    cout <<Fibonacci_sequence(n,m)<<endl;
}
// 64 位输出请用 printf("%lld")