vector - Heapsort in C, index 0 issue -

for project school have decided solve problem coding heapsort have issue. ("vector" vector sort , "n" number of elements in "vector")

here code :

void fixheap(int position,int length) {     int next=2*position;     int temp;      while (next<=length)     {         if (next<length && vector[next]<vector[next+1])         {             next++;         }         if (vector[position]<vector[next])         {             temp=vector[position];             vector[position]=vector[next];             vector[next]=temp;             position=next;             next=2*position;         }         else         {             return;         }     } }  void heapsort() {     int counter;     int temp;      for(counter=(n-1)/2;counter!=0;counter--)     {         fixheap(counter,n-1);     }     for(counter=n-1;counter>0;counter--)     {         temp=vector[counter];          vector[counter]=vector[0];         vector[0]=temp;         fixheap(0,counter-1);     }     display(); } 

when i'm doing fixheap(0,n-1) i'm putting next 0 , position @ 0 i'm not doing heap right. me fixing it?

also there other mistakes spotted may have overlooked?

the children of i-th node are @ 2*i , 2*i+1. if want sort every item in array, 1st node @ index 0. need fix child node index calculations accordingly.