Answer to Question #275304 in C for Lucky

Question

Given an array arr[] sorted in ascending order of size N and an integer K.

Check if K is present in the array or not. (Use Binary Search)

Input: N = 5

K = 6

arr[] = {1,2,3,4,6}

Output: 1

Explanation: Since, 6 is present in the array at index 4 (0-based indexing),

output is 1

Answer 1

#include <stdio.h>

int bin_search(int *arr, int n, int target) {
  int l = 0, r = n;
  while (l < r) {
    int m = (l + r) / 2;
    if (arr[m] == target) return m;
    if (arr[m]  < target) r = m;
    if (arr[m]  > target) l = m;
  }
  return -1;
}

int main() {
  int arr[5] {1, 2, 3, 4, 6};
  int k = 6;
  int i = bin_search(arr, 5, k);
  if (i != -1) printf("Item found at position %d", i);
  else printf("Item not found!");
}