luyang 2022-08-01 19:24:54 10 返回题目
#include <bits/stdc++.h> using namespace std; long long a[20000]; int main() { int b; cin >> b;
a[1] = 1; a[2] = 1; for (int i = 3; i <= b; i++) { a[i] = a[i - 1] + a[i - 2]; } cout << a[b];
}
