CCF CSP201803-1跳一跳（c++100）

CCF CSP201803-1跳一跳

#include<iostream>
using namespace std;
int main(){
	int n,ans = 0, num = 0;
	cin>>n;
	while(n != 0){
		if(n == 1){
			ans += n;
			num = 0;
		}
		else if(n == 2){
			ans += n + num;
			num += 2;
		}
		cin>>n;
	} 
	cout<<ans<<endl;
	return 0;
}