segment tree

/*
Please note that it's Function problem i.e.
you need to write your solution in the form of Function(s) only.
Driver Code to call/invoke your function would be added by GfG's Online Judge.*/


/* The functions which
builds the segment tree */
int *constructST(int arr[],int n)
{
  //Your code here
  int st[4*n]; //size
  for(int i=0;i<4*n;i++){
      st[i]=5000;
  }
  buildSegmentTree(st,arr,0,n,0);
  return st;
 }
/* The functions returns the
 min element in the range
 from a and b */
int RMQ(int st[] , int n, int a, int b)
{
//Your code here
query(st,0,n,a,b);

}

}
void buildSegmentTree(int st[],int arr[],int low ,int high,int pos){
    if(low==high){
        st[pos]=arr[low];
        return;
    }
    int mid =(low+high)/2;
    int left=buildSegmentTree(st,arr,low,mid,2*pos+1);
    int right=buildSegmentTree(sr,arr,mid+1,high,2*pos+2);
    st[pos]=min(left,right);
}

int  query(int st[],int low , int high ,int a,int b){
    if(low<=a && high >=b){
        return st[low/2];
    }else if (high <a || low >b ){
        return 5000;

    }else{
        int mid =(low+high)/2;
        return min(query(st,low,mid,a,b),query(st,mid+1,high,a,b));
    }


}