usaco1.1.3 Friday the Thirteenth 题解

【算法】模拟　　【难度】☆☆☆☆☆

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很简单的模拟题，关键是读清楚题，注意如何判断闰年。

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 1 /*
 2 ID: wsc5001
 3 LANG: C
 4 TASK: friday
 5 */
 6 #include<stdio.h>
 7 int runnian(int y)
 8 {
 9     if (y%100==0)
10     {
11         if (y%400==0)
12             return 1;
13         else
14             return 0;
15     }
16     if (y%4==0)
17         return 1;
18 }
19 int xingqi(int yu)
20 {
21     switch (yu)
22     {
23         case 0:return 6;
24         case 1:return 7;
25         default:return yu-1;
26     }
27 }
28 int main()
29 {
30     FILE *fin,*fout;
31     fin=fopen("friday.in","r");
32     fout=fopen("friday.out","w");
33     int i,j,n,runyear,tongji[8]={0},dayone=1,t;
34     fscanf(fin,"%d",&n);
35     for(i=0;i<n;i++)
36     {
37         runyear=runnian(1900+i);
38         for(j=1;j<=12;j++)
39         {
40             t=xingqi((dayone+13)%7); 
41             tongji[t]+=1;
42             if(j==2)//二月
43             {
44                 if (runyear==1)
45                     dayone=xingqi(dayone+29+1); //闰年 
46                 else
47                     dayone=xingqi(dayone+28+1); 
48             }
49             else if(j==4||j==6||j==9||j==11)//小月
50                 dayone=xingqi(dayone+30+1);
51             else//大月
52                 dayone=xingqi(dayone+31+1);  
53         }
54     }
55     fprintf(fout,"%d %d %d %d %d %d %d\n",tongji[6],tongji[7],tongji[1],tongji[2],tongji[3],tongji[4],tongji[5]);
56     //printf("%d %d %d %d %d %d %d\n",tongji[6],tongji[7],tongji[1],tongji[2],tongji[3],tongji[4],tongji[5]);
57     fclose(fin);
58     fclose(fout);
59     //getchar();
60 }