binary search in C++

binsearch.cpp

#include <vector>
#include <math.h>
#include <iostream>

using namespace std;

//get the index of a target integer from a sorted vector
int binSearch(const vector<int>& sorted, const int target){
  const int mid = floor(sorted.size()/2);

  if (sorted[mid] == target){
    //return if it matches
    return mid;
  }
  else if (sorted[mid] > target){
    //search left
    const vector<int> left(sorted.begin(),sorted.begin()+mid);
    return binSearch(left, target);
  }
  else{
    //search right
    const vector<int> right(sorted.begin()+mid,sorted.end());
    return (mid + binSearch(right, target));
  }
}

int main(){
  vector<int> v;
  for (int i=0; i<50; i++){
    v.push_back(2*i);
  }
  int result = binSearch(v,14); //expect the answer to be 7

  cout<<(result == 7)<<'\n';
}