Merge Sort

mergesort.c

void mergeSort(int a[ ], int n)‏
{
	int endcstr, endbstr, check, finished = 0;  	//  booleans
	int i, j, k, maxc, maxb;
	int *b, *c;				//  pointers for arrays	
	b = (int *) malloc( n * sizeof(int) );
	c = (int *) malloc( n * sizeof(int) );
	while ( !finished )‏
	{		//  distribution pass
		i = j = k = 0;
		while (i < n)‏
		{
			b[j++] = a[i++];
			while (i < n && a[i-1] <= a[i])  
				b[j++] = a[i++];  
	
			if (i < n)  
			{  
				c[k++] = a[i++];  
				while (i < n && a[i-1] <= a[i])    
					c[k++] = a[i++];   
			}
		}	// end distribution pass

		maxb = j;  maxc = k; check = 0;
		i = j = k = 0;		 // merge pass
		while ( i < n )	
		{
			check++;
			endbstr = maxb<=j;
			endcstr = maxc<=k;
			while (!endbstr || !endcstr)  
			{  
				if( !endbstr && (endcstr || b[j] < c[k]))‏
				{  
					a[i++] = b[j++];     
					endbstr = maxb<=j || b[j]<b[j-1];    
				}  
				else  
				{  
					a[i++] = c[k++];    
					endcstr = maxc<=k || c[k]<c[k-1];    
				} 
			} 
		}		// end merge pass
		finished = check <= 1;
	}
}