solutions/The Last Algorithms Course You'll Need/4. Binary Search.c

#include "stdio.h"

#define SIZE 4096

// The complexity is O(log n)
// because we always half the amount
// like N/2 -> N/4 -> N/8 ... N/(2^k) which equals log n

int binary_search(int array[], int size, int offset, int value)
{
	int pivot = size / 2;
	int current_value = array[offset + pivot];
			printf("At %d\n", offset + pivot);

	if (current_value == value)
	{
		return 1;
	}
	

	if (pivot > 0)
	{
		if (current_value > value)
			return binary_search(array, pivot, offset, value);
		else
			return binary_search(array, pivot, offset + pivot, value);
	}
	
	return 0;
}

int main()
{
	int array[SIZE];
	for (int i = 0; i < SIZE; ++i)
		array[i] = i;

	printf("1 if found: %d\n", binary_search(array, SIZE, 0, 5243));
	printf("1 if found: %d\n", binary_search(array, SIZE, 0, 1));
	printf("1 if found: %d\n", binary_search(array, SIZE, 0, 1044));
//	for (int i = 0; i < SIZE; ++i)
//		if (!binary_search(array, SIZE, 0, i))
//			printf("YOU FUCKED UP!!! at index %d\n", i);
	printf("1 if found: %d\n", binary_search(array, SIZE, 0, SIZE));
	array[14] = 13;
	printf("1 if found: %d\n", binary_search(array, SIZE, 0, 14));

}