二分查找最后一个小于等于和第一个大于等于某对象的数组元素位置

funny：

int findLastLE(int *array, int n, int target) // satisfy condition: array[?] <= target and the last one
{
	int start = 0, end = n - 1;
	while (start <= end) {
		int mid = (start + end) / 2;
		if (array[mid] <= target)
			start = mid + 1;
		else if (array[mid] > target)
			end = mid - 1;
	}
	
	if (start == 0)
		return -1;

	return start - 1;
}

int findFirstGE(int *array, int n, int target) // satisfy condition: array[?] >= target  and the first one
{
	int start = 0, end = n - 1;
	while (start <= end) {
		int mid = (start + end) / 2;
		if (array[mid] < target)
			start = mid + 1;
		else if (array[mid] >= target)
			end = mid - 1;
	}
	if (end == n - 1)
		return -1;
	return end + 1;
}