题解 | 二维斐波那契数列

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