(简单模拟2.1.1)POJ 2017 Speed Limit(跨项累加sumLen += (t2-t1)*v )

/*
* POJ_2017.cpp
*
*  Created on: 2013年10月24日
*      Author: Administrator
*/
#include <iostream>
#include <cstdio>

using namespace std;

int main() {
int n;

while (scanf("%d", &n) != EOF, n != -1) {
int t1 = 0, t2 = 0, v = 0;
int sumLen = 0;
int i;
for (i = 0; i < n; ++i) {
t1 = t2;
scanf("%d%d", &v, &t2);
sumLen += (t2 - t1) * v;
}

printf("%d miles\n",sumLen);
}

return 0;

}