2017.cpp

这些是我到目前在PKU上做出的题目

#include <iostream.h>
int main()
{int n,t,i,j,time,sum;
 cin>>n;
 while (n!=-1)
 {sum=0;time=0;
  for (t=1;t<=n;t++)
  {cin>>i>>j;
   sum=sum+i*(j-time);time=j;
   }
  cout<<sum<<" miles\n";
  cin>>n;
  }
  return 0;
}