日期模拟

#include<bits/stdc++.h>
using namespace std;
int cnt;
int yue[]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int rn(int x) {
    return (x%4==0&&x%100) || (x%400==0);
}
int main(){
    int n,y,r,w;
    n=1937,y=1,r=1,w=5;
    while(1){
        r=r%yue[y]+1;
        if(r==1) y=y%12+1;
        if(y==1&&r==1) n++;
        if(y==2){
            if(rn(n)) yue[y]=29;
            else yue[y]=28;
        }
        w=w%7+1;
        if(w%7==1) cnt++;
        if(n==2021&&y==3&&r==20) break;
    }
    cout << cnt;
    return 0;
}