Classical Binary Search

int binarySearch(vector<int> &v, int target, int start, int end){ // pass start and end into the list so that we do not need to make copies of the vector if (start >= end || start < 0 || end > v.size()-1){ // edge cases return -1; } int mid = start + (end - start) / 2; if (v[mid] == target){ return mid; } else if (v[mid]) > target){ // search left half binarySearch(v, target, start, mid-1); } else if (v[mid] < target){ // search right half binarySearch(v, target, mid+1, end); } return -1; }