贪心/poj 1922 Ride to School

 1 #include<cstdio>
 2 #include<cmath>
 3 using namespace std;
 4 int n,ans,v,t;
 5 int main()
 6 {
 7     scanf("%d",&n);
 8     while (n!=0)
 9     {
10         ans=0x7fffffff;
11         for (int i=1;i<=n;i++)
12         {
13             scanf("%d%d",&v,&t);
14             if (t>=0)
15             {
16                 int y=int(ceil(4500/(v*10.0/36.0)))+t;
17                 if (ans>y) ans=y;
18             }
19         }
20         printf("%d\n",ans);
21         scanf("%d",&n);
22     }
23     return 0;
24 }