binary search program c 2b 2b

1#include <iostream>
2using namespace std;
3
4// This program performs a binary search through an array, must be sorted to work
5int binarySearch(int array[], int size, int value) 
6{   
7    int first = 0,         // First array element       
8    last = size - 1,       // Last array element       
9    middle,                // Mid point of search       
10    position = -1;         // Position of search value   
11    bool found = false;        // Flag   
12    while (!found && first <= last) 
13    {      
14        middle = (first + last) / 2;     // Calculate mid point      
15        if (array[middle] == value)      // If value is found at mid      
16    	{         
17                found = true;         
18                position = middle;      
19        }      
20        else if (array[middle] > value)  // If value is in lower half         
21            last = middle - 1;      
22        else         
23            first = middle + 1;          // If value is in upper half   
24    }   
25    return position;
26}
27int main ()
28{
29    const int size = 5; // size initialization
30    int array[size] = {1, 2, 3, 4, 5}; // declare array of size 10
31    int value; // declare value to be searched for
32    int result; // declare variable that will be returned after binary search
33
34    cout << "What value would you like to search for? "; // prompt user to enter value
35    cin >> value;
36    result = binarySearch(array, size, value);
37
38    if (result == -1) // if value isn't found display this message
39        cout << "Not found\n";
40    else  // If value is found, displays message
41        cout << "Your value is in the array.\n"; 
42  
43    return 0;
44}

1#include<iostream> 
2using namespace std; 
3int binarySearch(int arr[], int p, int r, int num) { 
4   if (p <= r) { 
5      int mid = (p + r)/2; 
6      if (arr[mid] == num)   
7         return mid ; 
8      if (arr[mid] > num)  
9         return binarySearch(arr, p, mid-1, num);            
10      if (arr[mid] < num)
11         return binarySearch(arr, mid+1, r, num); 
12   } 
13   return -1; 
14} 
15int main(void) { 
16   int arr[] = {1, 3, 7, 15, 18, 20, 25, 33, 36, 40}; 
17   int n = sizeof(arr)/ sizeof(arr[0]); 
18   int num = 33; 
19   int index = binarySearch (arr, 0, n-1, num); 
20   if(index == -1)
21      cout<< num <<" is not present in the array";
22   else
23      cout<< num <<" is present at index "<< index <<" in the array"; 
24   return 0; 
25}