ZCO 2016 Bamboo Art

My solution keeps giving me a TLE and it always returns 1 when I test it.

#include <iostream> 


int binary_search(int arr[] , int x , int l , int r) {
	int mid;
	while (r > l) {
		mid = (l+r)/2;
		if (arr[mid] == x) {
			return 0;
			break;
		}
		if (mid < x) {
			l = mid + 1 ;
		}
		if (mid > x) {
			r = mid - 1;
		}
	}
	return -1;
}
int main() {
	int n;
	std::cin >> n;
	int arr[n];
	int diff,current,a_count = 0 , m_count = 0;
	bool found;
	for (int i = 0; i < n ; ++i) {
		std::cin >> arr[i];
	}
	std::sort(arr,arr+n);
	for (int i = 0; i < n; ++i) {
		for (int z = i+1 ; z < n; ++z) {
			diff = arr[z] - arr[i];
			current = arr[z];
			while (1) {
				if (binary_search(arr,current,0,n-1) == 0) {
					++a_count;
					current += diff;
				} 
				else {
					if (a_count > m_count) {
						m_count = a_count;

					}
					a_count = 0;
					break;
				}

			}
		}
	}
	std::cout << m_count + 1;
	return 0;

}

Here I have used max as the maximum number of heights.

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