2501 Average Speed

1. /*
3.   第一行的速度可能为0，故初始速度要为0
6.   */
8. #include<iostream>
9. using namespace std;
11. int main()
12. {
13.     freopen("in.txt","r",stdin);
14.     int h,m,s,k(0);
15.     int pres(0),nows,time;
16.     double sum=0.0;
17.     char c;
18.     while(scanf("%d%c%d%c%d",&h,&c,&m,&c,&s)!=EOF)
19.     {
20.         c=getchar();
21.         if(h==24)
22.             h=0;
23.         if(c!='/n')
24.         {
25.         
26.             if(pres!=0)
27.             {
28.             nows=s+m*60+h*60*60;
29.             time=nows-pres;
30.             sum+=time*k/3600.0;
31.             }
32.                 cin>>k;
35.         }
36.         else
38.         {
39.         
40.             nows=s+m*60+h*60*60;
41.             time=nows-pres;
42.             if(k!=0)
43.             sum+=time*k/3600.0;
45.             if(h<10)
46.                 cout<<0<<h<<":";
47.             else
48.                 cout<<h<<":";
49.             if(m<10)
50.                 cout<<0<<m<<":";
51.             else
52.                 cout<<m<<":";
53.             if(s<10)
54.                 cout<<0<<s<<" ";
55.             else
56.                 cout<<s<<" ";
58.             printf("%0.2lf km/n",sum);
59.         }
60.     
61.         pres=s+m*60+h*60*60;
62.     
63.     }
68.     return 0;
69. }

关键是输出格式的处理，还又要注意 24小时变为0小时