题解 | 函数实现计算一个数的阶乘
#include <iostream> using namespace std; long long factorial(int n); int main() { int n; cin >> n; cout << factorial(n) << endl; return 0; } long long factorial(int n) { // write your code here...... long long num=1;//注意定义long long while(n) { num*=n; n-=1; } return num; }