seg fault

[keithzhou]

hi I just wrote a function about the Breadth First Traversal. when i try to compile it,it return a seg fault error, i don't know how can i fix that , can anybody give a hint..

void Map::breadthFirstTraversal(int t)
//int *visited;
//cityMap is the container that store the names of city from a input file
{
	for(int i = 1 ; i<= cityMap.size(); i++)
	visited[i] = 0;
	queue <int> q;
	q.push(t);
	
	while(!q.empty())
	{
		int s = q.front();
		q.pop();
		visited[s] = 1;
		cout<<s<<endl;
		
		for(int i = 1; i<=cityMap.size(); i++)
		{
			if(cityMap.size()!=0 && visited[i] == 0)
			{
				q.push(i);
				visited[i] = 1;
			}		
		}
	}
}

thanks

[savavampir]

Any particular reason...
1. why are you skipping first element?
2. why are you past last element?

for(int i = 1 ; i<= cityMap.size(); i++)

[keithzhou]

sorry , i just mistype it, but since i change to int i = 0 , i<cityMap.size() i++.. it still return a seg fault.

[savavampir]

for(int i = 1; i<=cityMap.size(); i++)
{
	if(cityMap.size()!=0 && visited[i] == 0)

There is no need to check section in bold since loop will not run either if size is 0.

Generally whole code is a mess and pretty dangerous to use if you ask me, please if you can, reorganize your data better.

[Athar]

You need to run your program with the debugger, which will show you the line that causes the segmentation fault.
If you use GCC, you also should define _GLIBCXX_DEBUG, which will alert you to any out-of-bounds accesses in a standard container.