N1. Шаг в будущее

#include <iostream>
#include <vector>
using namespace std;

void co(vector <int> v){
    for (auto &x: v) cout<<x<<' ';
    cout<<'\n';
}
vector <int> cal = {-1, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
//31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
int dst = 0;
int day = -1, month = -1, year = -1, fst = -1;//first jan
void dist(){
    for (int i = 1;i<=12;++i){
        cout<<"mnth = "<<i<<'\n';
        if (i == month){
            cout<<" += "<<day<<'\n';
            dst += day;
            break;
        }
        else{
            cout<<"+= "<<cal[i]<<'\n';
            dst += cal[i];
        }
    }
}
int main()
{

    cin>>day>>month>> year>>fst;
    if (year % 4 == 0 && year % 100 != 0) {
            cal[2] = 29;
            //cal[4] = 31;
    }
    else if (year % 4 == 0 && year % 100 == 0 && year % 400 == 0){
        cal[2] = 29;
    }
    dist();
    cout<<"dst = "<<dst<<'\n';
    int ans;
    ans = ( fst + dst - 1) % 7;
    if (ans == 0) ans = 7;
    cout<<ans;
}
/*
29 02 2016 5
1+
01 01 2010 5
5+
31 12 2010 5
5 +
30 12 2010 5
4+
29 12 2010 5
3+
28 12 2010 5
2+
27 12 2010 5
1+
26 12 2010 5
7+
26 12 2016 5
1+
26 12 2000 6
2+
26 12 1900 1
3+
*/
//07 01 312 01
//7+