quicksort error

[zevlramos]

I need some help with my quicksort.
I keep getting error that vector subscript is out of range
Any help would be great

void quicksort(vector<int> &v,int low, int high)
{
	int middle = ( low + high ) / 2;
	if( v[ middle ] < v[ low ] )
		swap( v[ low ], v[ middle ] );
	if( v[ high ] < v[ low ] )
		swap( v[ low ], v[ high ] );
	if( v[ high ] < v[ middle ] )
		swap( v[ middle ], v[ high ] );

	int pivot = v[middle];
	swap( v[ middle ] , v[ high-1 ]);

		
		int i,j;
		for(i=low, j=high-1; ;)
		{
			while(v[i] < pivot){i++;}
			while(pivot < v[j]){j--;}
			if(i<j)
				swap( v[ i ] , v[ j ] );
			else 
				break;
		}
	
	
	swap( v[ i ], v[ high - 1 ] );
	
	quicksort(v,low,i-1 );
	quicksort(v,i + 1,high);
		

}
	
	

void quicksort(vector<int> &v)
{
	quicksort(v,0,v.size()-1);
}

[Tamao]

Hello there, if you are using visual studio then try setting a breakpoint and check what happens

*cheers*

[zevlramos]

I'm very new to visual studio, how can I setup a breakpoint?

[zevlramos]

Ah definitely solved my problem. I didnt tell the function what to do when we reached 2 or less nums in the vector

[Tamao]

Good job :), there should be a gray area in the VS editor if you click it you will get a red ball and that is the breakpoint, here is a picture of how it looks like when it's enabled:

http://blogs.msdn.com/blogfiles/endpoint/WindowsLiveWriter/Int.NETOutputCachingwithWCFWebHttpServic_DD70/BreakpointInVisualStudio_4.jpg


EDIT: and don't forget running your program in debug mode if you do so you will trigger it and you will then be able to see variable data and so on.