what's the problem

[denniscpp]

can someone tell me why this code doesnt work?

void room::emptyMB3()
{
	for(int i = 0; i < MB3.size(); i++)
	{
		MB3[i]->setstatus("UNASSIGNED");
	}
	for(int i = 0; i < students.size(); i++)
	{
		if(students[i] == MB3[i])
			students[i]->setstatus("UNASSIGNED");	
			noRoom.push_back(students[i]);
	}
	MB3.erase(MB3.begin(),MB3.end());
}

the problem here is noRoom.push_back(students[i]); doesnt work, it pushes back for the MB3.size()-1 instead of for students.size().

for example say my MB3.size() = 3 and my students.size() = 10

it will only push back students[i] when it is within MB3.size()-1 which is 2.

so if students[1] == MB3[1];
or students[2] == MB3[2];

it pushes back

but if it's 3 and above, it wont. i dont get why this happens. the setstatus seems fine so i dont get why push_back is not.

[eypros]

You don't tell what all your variables are.

Line 11 guessing from your indentation is not included in if. I guess that an error. Use brackets for this.
SO basically for your code you push_back for every element of students.

[denniscpp]

variables are vector<class student:int ID, string name, char gender, string status>MB3

i tried it using brackets as well and the result is the same.

[denniscpp]

i made a mini version of the code for you guys to try out. to check for elements in noRoom go to "list students" then "list students without rooms". for students go to "list all students". try creating 4-5 students then assign student 1 and 3 to block A1. after that check the elements of noRoom and students. then empty block A1 and check again. the problem will present itself then.

#include <iostream>
#include <vector>
#include <cstdlib>
#include <set>
#include <algorithm>
using namespace std;
class room;
class student;
class menu
{
	public:
	void mainmenu();
	void MAmenu();
	void MAdelmenu();
	void roomGo();
	void listSmenu();
};
class functions:public menu
{
	public:
	void add(room& r1, student*& s1, char choice);
	void addAB();
	void emptyAB();
	void addMA(char option,room& r1,student*& s1,char choice,int target,int num);
	void emptyMA(char option,room& r1,student*& s1,char choice,int target,int num);
	void addMA1(room& r1, student*& s1, char choice, int& target, int& num);
};
class student
{
private:
	string name, dummy, status;
	char gender;
	int ID;	
public:
	student() : name("UNKNOWN"), ID(0), gender('-'), status("UNASSIGNED"){}
	student (string Name, int ID, char Gender)
	{
		this->name = Name;
		this->ID = ID;
		this->gender = Gender;
	}
	student(const student& s): name(s.name), ID(s.ID), gender(s.gender){}
	void setstudent();
	void getstudent(string name, int ID, char gender, string status);
	void setstatus(string status) {this->status = status;}
	void print(int i) const;
	int getid(){return ID;}
};
void student::getstudent(string name, int ID, char gender, string status)
{
	this->name = name;
	this->ID = ID;
	this->gender = gender;
	this->status = status;
}
void student::setstudent()
{
	cout << "Enter student's ID: ";
	cin >> ID;
	cout << "Enter student's gender(M/F): ";
	cin >> gender;
	gender = toupper(gender);
	getline(cin, dummy);
	cout << "Enter student's name: ";
	getline(cin, name);
	cout << endl;
}
void student::print(int i) const
{
	cout << i+1 << ". ID: " << ID << " | NAME: " << name << 
	" l SEX: " << gender << " l ROOM: " << status << endl;
}
class room
{
private:
	vector<student*> students;
	vector<student*> noRoom;
	vector<student*> MA1;
public:
	void addstudent(student* s);
	void addnoRoom(student* s);
	void addMA1(int target);
	void emptyMA1();
	void printALL();
	void printnoRoom();
	void printMA1();
	void printRoom();
	int studentsize(){return students.size();}
	int noRoomsize() {return noRoom.size();}
	int roomMA1size(){return MA1.size();}
};
void room::addstudent(student* s)
{
	students.push_back(s);
}

void room::addnoRoom(student* s)
{
	noRoom.push_back(s);
}
void room::addMA1(int target)
{
	MA1.push_back(noRoom[target]);
	noRoom[target]->setstatus("MA1");
	for(int i = 0; i < students.size(); i++)
	{
		if(noRoom[target] == students[i])
			students[i]->setstatus("MA1");
	}
	noRoom.erase(noRoom.begin()+target);
}
void room::emptyMA1()
{
	for(int i = 0; i < MA1.size(); i++)
		MA1[i]->setstatus("UNASSIGNED");
	for(int i = 0; i < students.size(); i++)
	{
		if(students[i] == MA1[i])
		{
			students[i]->setstatus("UNASSIGNED");
			noRoom.push_back(students[i]);
		}
	}
	MA1.erase(MA1.begin(),MA1.end());
}
void room::printnoRoom()
{
	for(int i = 0; i < noRoom.size(); i++)
		noRoom[i]->print(i);
}

void room::printALL()
{	
	for(int i = 0; i < students.size(); i++)
		students[i]->print(i);
}
void room::printMA1()
{
	for(int i = 0; i < MA1.size(); i++)
		MA1[i]->print(i);
}
void room::printRoom()
{
	printMA1();
}
void functions::addMA(char option,room& r1,student*& s1,char choice,int target,int num)
{
	cout << "Choose option(1-10): ";
	cin >> option;
	option = toupper(option);
	switch(option)
	{
		case'1': addMA1(r1,s1,choice,target,num);
				 MAmenu();
				 addMA(option,r1,s1,choice,target,num);
				 break;
		case'9': roomGo();
		case'0': break;
	}
}
void functions::emptyMA(char option,room& r1,student*& s1,char choice,int target,int num)
{
	cout << "Choose Option(1-10): ";
	cin >> option;
	option = toupper(option);
	switch(option)
	{
		case'1': r1.emptyMA1();
				 MAmenu();
				 break;
		case'9': roomGo();
		case'0': break;
	}
}
room r1;
	menu m;
	int i = 0;
	functions f;
	student* s1 = NULL;
	int target;
	int num;
	bool done = false;
	char choice, option;
int main()
{do
	{
		m.mainmenu();
		cout << "Select option (1-6): ";
		cin >> option;
		option = toupper(option);
		switch (option)
		{
			case'1': f.add(r1,s1,choice);
						break;
			case'3': m.roomGo();
					 f.addAB();
						break;			
			case'5': m.roomGo();
					 f.emptyAB();
						break;		
			case'6': m.listSmenu();
						break;
			case'8': done = true;
						break;
		}
	}
	while(!done);
	return 0;
}
void menu::mainmenu()
{
cout <<"|[1] Add student                            |" << endl <<
	"|[3] Assign rooms                           |" << endl <<
	"|[5] Empty rooms                            |" << endl <<
	"|[6] List students                          |" << endl;
}
void menu::listSmenu()
{
	system("cls");
	cout << "*====================================*" << endl <<
	"|@Students Log                       |" << endl <<
	"|------------------------------------|" << endl <<
	"|[1] List All students               |" << endl <<
	"|[2] List students with rooms        |" << endl <<
	"|[3] List students without rooms     |" << endl <<
	"|[4] back to main                    |" << endl <<
	"*=====================================+" << endl << endl;
	cout << "Choose Option (1-4): ";;
	cin >> option;
	option = toupper(option);
	switch(option)
	{
		case'1': r1.printALL();
				 system("pause");
				 listSmenu();
				 break;
		case'2': r1.printRoom();
				 system("pause");
				 listSmenu();
				 break;				 
		case'3': r1.printnoRoom();
				 system("pause");
				 listSmenu();
				 break;				 
		case'4': break;
	}
}
void menu::MAmenu()
{
	system("cls");
    cout << "|[1] A1 (" << 2-r1.roomMA1size() <<")|" << endl << endl;
}
void menu::MAdelmenu()
{
	system("cls");
    cout << "|[1] A1 (" << r1.roomMA1size() <<")|" << endl << endl;
}
void menu::roomGo()
{
	system("cls");
	cout << "*====================*" << endl <<
	"|@MALE HOSTELS(M)    |" << endl <<
	"|--------------------|" << endl <<
	"|[1] Block A         |" << endl << endl;
}
void functions::add(room& r1, student*& s1, char choice)
{
	cout << "Add student? (Y/N):";
	cin >> choice;
	while (toupper(choice) == 'Y')
	{
		s1 = new student;		
		s1->setstudent();
		r1.addstudent(s1);
		r1.addnoRoom(s1);
		cout << "add more students?(Y/N): ";
		cin >> choice;
	}
	cout << endl;
	system("cls");
	r1.printALL();
	system("pause");
}
void functions::addAB()
{
	cout << "Choose Hostel Block(1-2: Male, 3-4: Female): ";
	cin >> option;
	option = toupper(option);
	switch(option)
	{
		case'1': MAmenu();
				 f.addMA(option,r1,s1,choice,target,num);
				 break; 
		case'5': break;
	}
}
void functions::emptyAB()
{
	cout << "Choose Hostel Block(1-2: Male, 3-4: Female): ";
	cin >> option;
	option = toupper(option);
	switch(option)
	{
		case'1': MAmenu();
				 f.emptyMA(option,r1,s1,choice,target,num);
				 break;				 
		case'5': break;
	}
}
void functions::addMA1(room& r1, student*& s1, char choice, int& target, int& num)
{
	cout << "Assign to room A1? (Y/N):";
	cin >> choice;
	num = 2;					
	while (toupper(choice) == 'Y' && num > r1.roomMA1size())
	{
		r1.printnoRoom();
		cout << "choose student(1-" << r1.noRoomsize() << "): ";
		cin >> target;
			if(target > r1.noRoomsize() || target <= 0)
			{
				cout << "Invalid Student\n";
				break;
			}
		target--;					
		r1.addMA1(target);						
		cout << "Assign more?(Y/N) CAPACITY LEFT = " << num - r1.roomMA1size() << " :";
		cin >> choice;
			if(r1.noRoomsize()== 0)
			{
				cout << "no more student" << endl;
				system("pause");
				break;
			}			
	};
	r1.printMA1();
	if(r1.roomMA1size() == 2)
	{
	cout << endl;
	cout << "capacity reached\n\n";
	}
	system("pause");
}