A problem with STL list

[john22]

Hello there,

so I've created a code with STL list which works just fine
Here is the code

// here is main.h file
#include <iostream>
#include <iomanip>
#include <list>

using namespace std;

class Person
{

public:

//Person();
//~Person();

int getPosition()
{
return position;
};

void setPosition(int n)
{
position = n;
};

private:
int position;
};

//here is main.cpp file

#include "main.h"
int main ()
{
list <Person> circ;
Person player;

int i;
for (i = 0; i < 4; i++) // insert players into the circle
{
player.setPosition(i);
circ.push_back(player);
}

int remove = 0;

list<Person>::iterator j = circ.begin();

while (j!= circ.end())
{
if (j->getPosition() == remove) // if the player has the target
// position
{
j = circ.erase(j); // eliminate player from the circle
}
j++;
}

for (j = circ.begin(); j != circ.end(); j++)
cout << j->getPosition();
cout << endl;
}

My problem is when I set the variable "remove" to be = 3 which is I think the end of the list, the program crashes directly, but when I assign it from 0 - 2 it works just fine. Can anyone help me fixing this, please?

[Disch]

Don't see any problems. Also it works just fine for me with remove==3.

EDIT: doh, yeah I see it now. Strange how I missed it when someone had the exact same problem earlier today.

Also strange how it doesn't crash for me....

[cire]

If you "remove" the last element with that code, j is set to circ.end(), then you increment it causing undefined behavior.

while (j!= circ.end())
{
    if (j->getPosition() == remove)
        j = circ.erase(j); // eliminate player from the circle
    else
        ++j;
}

[Angeljruiz]

Please enclose your source code in code tags next time
But it isnt crashing for me

[john22]

OH I spent 3 hours to fix it! I didn't know how small mistake it is!

THANK YOU cire so much