int binarySearch(vector<int> &arr,int low,int high,int target){
    int mid=(low+high)/2;
    if(low>high) return -1;
    if(arr[mid]==target) return mid;
    else if(arr[mid]>target) return binarySearch(arr, low, mid-1,target);
    else return binarySearch(arr, mid+1, high,target);

}
int search(vector<int> &arr, int target) {
    int n=arr.size();
    int low=0;
    int high=n-1;
    binarySearch(arr, low,high,target);
}