折半查找（迭代）——ANSI C实现

typedef int ElementType;

int Search(ElementType *arr, int size, ElementType key) {
	int low = 0, high = size - 1, mid = (low + high) / 2;
	while (low <= high) {
		if (key < arr[mid])
			high = mid - 1;
		else if (key > arr[mid])
			low = mid + 1;
		else if (key == arr[mid])
			return mid;
		mid = (low + high) / 2;
	}

	return -1;
}

int main() {

	int size = 30;
	int max = 300;
	int *array = GetRandomArray(size, max);
	printf("Original ");
	PrintArray(array, size);
	Sort(array, size);
	printf("Sorted   ");
	PrintArray(array, size);

	srand(clock());
	int key = rand() % max;
	int pos = Search(array, size, key);
	if (pos != -1)
		printf("Key element %d has been found in position %d of this array...", key, pos);
	else
		printf("Cannot find key element %d in this sorted array...", key);

	return 0;
}