#include <iostream>
#include <bits/stdc++.h>using namespace std;
int IsLeapyear(int year)//判断闰年
{if((year%4==0&&year%100!=0)||year%400==0)//百度一下你就知道为何这样判断闰年{return 1;}else{return 0;}
}
int DaysofMonth(int year,int month)//返回这个月有几天
{if(month>0&&month<=7)//1-7月{if(month%2==1){return 31;//1，3，5，7月都是31天}else{if(month==2)//2月有点特殊return 28+IsLeapyear(year);else return 30;//4，6月30天}}else if(month>7&&month<=12)//8-12月{if(month%2==0)return 31;//8，10，12月31天else return 30;//9，11月30天}else//不合法{return 0;}}
int DayInYear(int year,int month,int day)//返回这一年的第几天
{int days=day;month--;while(month){days+=DaysofMonth(year,month);month--;}return days;
}
int IFDate(int year,int month,int day){//判断是否是合法日期if(year<0||month<1||month>12||day>31||day<1){return 0;}else{if(day>DaysofMonth(year,month)){return 0;}}return 1;
}
int WeekDay(int year,int month,int day){//以今天：2020/10/27，星期二为基准int days,before=1;//days为距今的天数，今天之前before=-1；今天及之后before=1if(year<2020){//2020年以前before=-1;days=365-DayInYear(year,month,day)+IsLeapyear(year);for(int i=year+1;i<2020;i++){if(IsLeapyear(i)){days+=366;}else{days+=365;}}days+=301;//DayInYear(2020,10,27)=301}else if(year==2020){if(month<10){before=-1;days=DaysofMonth(year,month)-day;for(int i=month+1;i<10;i++){days+=DaysofMonth(year,i);}days+=27;}else if(month==10){if(day>=27){days=day-27;}else {before=-1;days=27-day;}}else{days=DayInYear(year,month,day)-301;}}else{//2020年以后days=65;//366-301=65for(int i=2021;i<year;i++){if(IsLeapyear(i)){days+=366;}else{day+=365;}}days+=DayInYear(year,month,day);}days*=before;int weekday=days%7+2;//直觉告诉我这么做，至于为什么我不会解释，规律好像就是这样if(weekday<=0){//小于0，加7weekday+=7;}if(weekday>7){//大于7，减去7weekday-=7;}return weekday;
}void spiliteBy(string s,char by,string* sub){//字符串分割，分割符by,字串为subint n=0;int last=0;int len=s.length();for(int i=0;i<len;i++){if(s[i]==by){sub[n]=s.substr(last,i-last);n++;last=i+1;}}sub[n]=s.substr(last,len-last);
}
int StringToInt(string s){//字符串转为整形，字符串必须全为整数型字符0-9int len=s.length();int a=0;int num=0;for(int i=0;i<len;i++){a=s[i]-'0';num*=10;num+=a;}return num;
}
int main()
{int testNum=1;while(testNum--){int year,month,day;string s;cout<<"请输入日期,格式：2001/01/01"<<endl;cin>>s;string date[3];//默认分割为三个子串spiliteBy(s,'/',date);//分割year=StringToInt(date[0]);month=StringToInt(date[1]);day=StringToInt(date[2]);//cin>>year>>month>>day;cout<<year<<month<<day<<endl;if(IFDate(year,month,day)){cout<<year<<"年的第"<<DayInYear(year,month,day)<<"天,星期"<<WeekDay(year,month,day)<<endl;}else{cout<<"请输入合法日期"<<endl;}}return 0;
}