POJ 2017 计算公路里程 模拟题

#include <iostream>
using namespace std;

int main(){
	int n,s[11],t[11];
	int i,ret;
	while(cin>>n, n != -1){
		ret = 0;
		memset(s, 0, sizeof(s));
		memset(t, 0, sizeof(t));
		for(i = 1; i <= n; i++){
			cin>>s[i]>>t[i];
			ret += s[i] * (t[i] - t[i - 1]);
		}
		cout<<ret<<" miles"<<endl;
	}
	return 0;
}