arrayscbinary-searchfind-occurrences

first occurrence code binary search debug in c

int firstOcc(int a[],int m,int x)
{
    int high=m-1,low=0,mid,index=-1;

    while(low<=high){
    mid=(low+high)/2;

    if(a[mid]<x){
        mid=low+1;}

    if(a[mid]>x){
        mid=high-1;}

    if(a[mid]==x){
        index=mid;
        high=mid-1;}
    }

    return index;
}

why is my function isn't working ?! finding first occurrence. what is wrong with it ?

can't find the bug, copied almost identical code from the internet it worked but I need to know why my code isn't working

Solution

  • wrong:

            mid=low+1;}
…
        mid=high-1;}

    right:

            low=mid+1;}
…
        high=mid-1;}

    mid change is off the table.