【 OJ 】 HDOJ1001 n!求和 [ 2 ]

这题没什么蛋疼了，还好2-3次也算AC了

# include<iostream>
using namespace std;
int sum(int n) {
	int sum = 0;
	for (int i = 1; i <= n; ++i)
		sum += i;
	return sum;
}

int main(void) {
	int n;
	while (cin >> n) {
		cout << sum(n) << endl<<endl;
	}
	return 0;
}