Previous and Next Date in C++

	#include <bits/stdc++.h>

	using namespace std;

	map<string,int>day,month;

	vector<int> helper(int d,int m,int y){
	if (d > 0 && d < 28) {
	d += 1;
	}
	if (d == 28) {
	if (m == 2) {
	if ((y % 400 == 0) \|\| (y % 100 != 0 \|\| y % 4 == 0)) {
	d = 29;
	} else {
	d = 1;
	m = 3;
	}
	} else {
	d += 1;
	}
	}
	if (d == 29) {
	if (m == 2) {
	d = 1;
	m = 3;
	} else {
	d += 1;
	}
	}
	if (d == 30) {
	if (m == 1 \|\| m == 3 \|\| m == 5 \|\| m == 7 \|\| m == 8 \|\| m == 10 \|\| m == 12) {
	d += 1;
	} else {
	d = 1;
	m += 1;
	}
	}
	if (d == 31) {
	d = 1;
	if (m == 12) {
	y += 1;
	m = 1;
	} else {
	m += 1;
	}
	}
	return {d,m,y};
	}

	vector<int> helper2(int d,int m,int y){
	return {};
	}

	struct date{
	int date;
	string currDay;
	string currMonth;
	int year;
	};

	string next(date d){
	int date = d.date;
	int mon = month[d.currMonth];
	int year = d.year;
	vector<int> v = helper(date,mon,year);
	string nextday="",nextmonth="";
	for(auto i:day)if(i.second==(day[d.currDay]+1)%7)nextday=i.first;
	for(auto i:month)if(i.second==v[1])nextmonth=i.first;
	cout<<nextday<<","<<v[0]<<" "<<nextmonth<<" "<<v[2]<<endl;
	return "";
	}

	string prev(date d){
	return "";
	}

	int main (){

	day["Mon"]=1;
	day["Tue"]=2;
	day["Wed"]=3;
	day["Thu"]=4;
	day["Fri"]=5;
	day["Sat"]=6;
	day["Sun"]=0;

	month["Jan"]=1;
	month["Feb"]=2;
	month["March"]=3;
	month["April"]=4;
	month["May"]=5;
	month["June"]=6;
	month["July"]=7;
	month["Aug"]=8;
	month["Sep"]=9;
	month["Oct"]=10;
	month["Nov"]=11;
	month["Dec"]=12;

	date d;
	d.currDay="Tue",d.date=21,d.currMonth="March",d.year=2023;
	next(d);

	return 0;
	}