BinarySearch.cpp

int BinarySearch(int a[], int size, int p) {
	int L = 0;
	int R = size - 1;
	while (L <= R) {
		int mid = (L + R) / 2;
		if (p == a[mid]) {
			return mid; 
		} else if (p > a[mid]) {
			L = mid + 1;
		} else {
			R = mid - 1;
		}
	}
	return -1;
}