recurrsive function goes into infinte loop

[nabh4u]

hi, i have a functionn sort_and_count where i will sort a vector and count the number of inversions. i will first divide the list into two n call the function recurrsively. problem is its going on,doesnt stop. please can you tell me why is this problem here? this implements merge sort also.
here's the sample code:

int sort_and_count(int Left,int Right)
{
     int Mid;
     int count=0,countL=0,countR=0;
     if(Left==Right)
     {
          return count=0;
     }
     else
     {
          Mid=(Left+Right+1)/2;
          countL = sort_and_count(Left,Mid);
          countR = sort_and_count(Mid+1,Right);
          count = merge_count(Left,Mid,Right);
          return count=count+countL+countR;
     }    
}

thank you in advance..

[iLL]

hi, i have a functionn sort_and_count where i will sort a vector and count the number of inversions. i will first divide the list into two n call the function recurrsively. problem is its going on,doesnt stop. please can you tell me why is this problem here? this implements merge sort also.
here's the sample code:

int sort_and_count(int Left,int Right)
{
     int Mid;
     int count=0,countL=0,countR=0;
     if(Left==Right)
     {
          return count=0;
     }
     else
     {
          Mid=(Left+Right+1)/2;
          countL = sort_and_count(Left,Mid);
          countR = sort_and_count(Mid+1,Right);
          count = merge_count(Left,Mid,Right);
          return count=count+countL+countR;
     }    
}

thank you in advance..

There is something wrong with your equation

1 = (0 + 1 + 1)/2 // Integral math

In the next line you state sort_and_count(Left,Mid); since Mid == Right, you’ll get into an infinite loop here.

Any time the difference between left and right is 1, then Mid == Right


therefore you’ll never get to the base case of left == right

[iLL]

Maybe (note that I haven’t try it) if your base case is:

if((Right == Left) || (Right – Left = 1))

[nabh4u]

There is something wrong with your equation

1 = (0 + 1 + 1)/2 // Integral math

In the next line you state sort_and_count(Left,Mid); since Mid == Right, you’ll get into an infinite loop here.

Any time the difference between left and right is 1, then Mid == Right


therefore you’ll never get to the base case of left == right

thanks for the insight...i have resolved the error...
the equations should be :
mid = (left+right)/2