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. usingnamespacestd;
11. intmain()
12. {
13. freopen("in.txt","r",stdin);
14. inth,m,s,k(0);
15. intpres(0),nows,time;
16. doublesum=0.0;
17. charc;
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. {
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. {
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("%0.2lfkm\n",sum);
59. }
61. pres=s+m*60+h*60*60;
63. }
68. return0;
69. }

关键是输出格式的处理，还又要注意 24小时变为0小时