A reworked

#define _CRT_SECURE_NO_DEPRECATE

#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <stack>

using namespace std;

pair<int, int> dec(pair<int, int> a, pair<int, int> b) {
	if (a.second < b.second) {
		a.second += 60;
		a.first--;
	}
	return { a.first - b.first, a.second - b.second };
}

pair<int, int> r(string a, string b) {
	pair<int, int> d1 = { (a[1] - '0') * 10 + (a[2] - '0'), (a[3] - '0') * 10 + (a[4] - '0') };
	pair<int, int> d2 = { (b[1] - '0') * 10 + (b[2] - '0'), (b[3] - '0') * 10 + (b[4] - '0') };

	if (a[0] != b[0]) {
		if (a[0] == '-') {
			return { d1.first + d2.first + (d1.second + d2.second) / 60, (d1.second + d2.second) % 60 };
		}
		return { -(d1.first + d2.first) + (d1.second + d2.second) / 60, (d1.second + d2.second) % 60 };
	}
	if (a[0] == '-') {
		if (d1 > d2) {
			return  dec(d1, d2);
		}
		auto v = dec(d2, d1);
		v.first *= -1;
		return v;
	}

	if (d1 < d2) {
		return  dec(d2, d1);
	}
	auto v = dec(d1, d2);
	v.first *= -1;
	return v;
}



int main() {
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);

	map<string, int> month;
	month["Jan"] = 1;
	month["Feb"] = 2;
	month["Mar"] = 3;
	month["Apr"] = 4;
	month["May"] = 5;
	month["Jun"] = 6;
	month["Jul"] = 7;
	month["Aug"] = 8;
	month["Sep"] = 9;
	month["Oct"] = 10;
	month["Nov"] = 11;
	month["Dec"] = 12;

	vector<int> kd = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
	vector<string> mnth = { "", "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

	string t;
	getline(cin, t);
	string ip, q, name, d, p, extra;
	while (cin >> ip) {
		cin >> q >> name;
		cin >> d;
		d.erase(d.begin());
		cin >> p;
		p.erase(p.begin() + 5);
		getline(cin, extra);

		auto v = r(p, t);
		if (v.first < 0) {
			v.second *= -1;
		}

		int dd = (d[0] - '0') * 10 + (d[1] - '0');
		string M = "   ";
		M[0] = d[3];
		M[1] = d[4];
		M[2] = d[5];
		int mm = month[M];
		int yy = (d[7] - '0') * 1000 + (d[8] - '0') * 100 + (d[9] - '0') * 10 + (d[10] - '0');
		int hh = (d[12] - '0') * 10 + (d[13] - '0');
		int mn = (d[15] - '0') * 10 + (d[16] - '0');
		int ss = (d[18] - '0') * 10 + (d[19] - '0');

		if (yy % 4 == 0) {
			kd[2]++;
		}

		mn += v.second;
		if (mn > 59) {
			hh++;
			mn = mn % 60;
		}
		else
			if (mn < 0) {
				mn += 60;
				hh--;
			}

		hh += v.first;
		if (hh > 23) {
			dd++;
			hh %= 24;
		}
		else {
			if (hh < 0) {
				hh += 24;
				dd--;
			}
		}

		if (dd > kd[mm]) {
			mm++;
			dd = 1;
			if (mm == 13) {
				yy++;
				mm = 1;
			}
		}
		if (dd == 0) {
			if (mm == 1) {
				yy--;
				mm = 12;
				dd = 31;
			}
			else {
				mm--;
				dd = kd[mm];
			}
		}


		d = "";
		d += (char)(dd / 10 + '0');
		d += (char)(dd % 10 + '0');
		d += "/" + mnth[mm] + "/";

		string date1 = ":";
		date1 += (char)(hh / 10 + '0');
		date1 += (char)(hh % 10 + '0');
		date1 += ':';
		date1 += (char)(mn / 10 + '0');
		date1 += (char)(mn % 10 + '0');
		date1 += ':';
		date1 += (char)(ss / 10 + '0');
		date1 += (char)(ss % 10 + '0');


		cout << ip << ' ' << q << ' ' << name << " [" << d << yy << date1 << ' ' << t << "]" << extra << endl;
	}
}