蓝桥杯 算法提高 日期计算

 1 #include<iostream> 
 2 #include<cstring>
 3 #include<cstdio>
 4 using namespace std;
 5 
 6 int a[2][13]={{0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}};
 7 
 8 bool isRun(int year){//判断是否为闰年
 9     if(year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
10         return true;
11     return false;
12 }
13 
14 int calDay(int year){
15     int index = 0;
16     if(!isRun(year)) index = 1;
17     int tot = 0;
18     for(int i=1; i<=12; ++i)
19         tot += a[index][i];
20     return tot;
21 }
22 
23 int Day(int y, int m, int d){//计算从0年0月0日到y年m月d日的时间天数 
24     int ans = 0;
25     for(int i=1; i<y; ++i)
26         ans+=calDay(i);
27     int index = 0;
28     if(!isRun(y)) index = 1;
29     for(int i=1; i<m; ++i)
30         ans += a[index][i];
31     ans += d;
32     return ans;
33 }
34 
35 int main(){
36     int y, m, d;
37     cin>>y>>m>>d;
38     int diff = Day(y, m, d) - Day(2011, 11, 11);//已知2011-11-11这一天是星期5 
39     if(diff > 0) cout<<(4+diff%7)%7+1<<endl;
40     else{
41         for(int i=1; i<=7; ++i)
42             if((i-1 + -diff%7)%7 + 1 == 5){
43                 cout<<i<<endl;
44                 break;
45             }
46     }
47     return 0;
48 }