Binary_Search.cpp

#include<iostream>
using namespace std;
int main() {
  int n, i, search, first, last, middle;
  cout << "Enter total number of elements :";
  cin >> n;
  int arr[n];
  cout << "Enter " << n << " number :";
  for (i = 0; i < n; i++) {
    cin >> arr[i];
  }
  cout << "Enter a number to find :";
  cin >> search;
  first = 0; last = n - 1;
  middle = (first + last) / 2;
  while (first <= last) {
    if (arr[middle] < search) {
      first = middle + 1;
    } else if (arr[middle] == search) {
      cout << search << " found at location " << middle + 1 << "\n";
      break;
    } else {
      last = middle - 1;
    }
    middle = (first + last) / 2;
  }
  if (first > last) {
    cout << "Not found! " << search << " is not present in the list.";
  }
}