binarysearch.c

#include <stdio.h> 
  
// A iterative binary search function. It returns 
// location of x in given array arr[l..r] if present, 
// otherwise -1 
int binarySearch(int arr[], int l, int r, int x) 
{ 
    while (l <= r) { 
        int m = l+ (r - l)/2; 
  
        // Check if x is present at mid 
        if (arr[m] == x) 
            return m; 
  
        // If x greater, ignore left half 
        if (arr[m] < x) 
            l = m + 1; 
  
        // If x is smaller, ignore right half 
        else
            r = m - 1; 
    } 
    return -1;
}
  
int main(void) 
{ 
    int n;
    scanf("%d",&n);
    int arr[n];

    for(int i=0;i<n;i++){
        scanf("%d",&arr[i]);
    }
    int x;
    printf("Enter the number to search\n");
    scanf("%d",&x);
  //Calling the binarySearch function
    int result = binarySearch(arr, 0, n - 1, x); 
    (result == -1) ? printf("Element is not present"
                            " in array") 
                   : printf("Element is present at "
                            "index %d", 
                            result); 
    return 0; 
}