binary_search.cpp File Reference

Binary search algorithm More...

#include <iostream>

Include dependency graph for binary_search.cpp:

Functions
int	binary_search (int a[], int r, int key)
int	main (int argc, char const *argv[])

Detailed Description

Binary search algorithm

Function Documentation

binary_search()

int binary_search	(	int	a[],
		int	r,
		int	key
	)

binary_search function

Parameters

[in]	a	array to sort
[in]	r	right hand limit = \(n-1\)
[in]	key	value to find

Returns

index if T is found

-1 if T is not found

                                           {
    int l = 0;
 
    while (l <= r) {
        int m = l + (r - l) / 2;
        if (key == a[m])
            return m;
        else if (key < a[m])
            r = m - 1;
        else
            l = m + 1;
    }
    return -1;
}

main()

int main	(	int	argc,
		char const *	argv[]
	)

main function

                                       {
    int n, key;
    std::cout << "Enter size of array: ";
    std::cin >> n;
    std::cout << "Enter array elements: ";
 
    int* a = new int[n];
 
    // this loop use for store value in Array
    for (int i = 0; i < n; i++) {
        std::cin >> a[i];
    }
 
    std::cout << "Enter search key: ";
    std::cin >> key;
 
    // this is use for find value in given array
    int res = binary_search(a, n - 1, key);
    if (res != -1)
        std::cout << key << " found at index " << res << std::endl;
    else
        std::cout << key << " not found" << std::endl;
 
    delete[] a;
    return 0;
}

Here is the call graph for this function: