#include <stdio.h>
void sort(int arr[],int len,int searchkey){
int low=0,high=len-1,mid,key=-1;
while(high>=low){
mid=(low+high)/2;
if(arr[mid]==searchkey){
key=mid+1;
break;
}else if(searchkey>arr[mid]){
low=mid+1;
}else{
high=mid-1;
}
}
printf("%d ",key);
}
int main () {
int arr[]={0,1,2,3,4,5,6,7,8,9};
sort(arr,sizeof(arr)/sizeof(int),5);
return 0;
}