與二分查詢法相似，也是必須先進行排序，對比二分查詢法只修改一行程式碼

int  binarySearch(void *p, int key ,int size ) {
	int *arr = p;
	//mid = (high + low) / 2  mid = hight + (low - high)* 一個比例
	int count = 0;					// mid = hight + (low - high)* 1.0 * key - arr[high]/arr[low]-arr[high]  //拉格朗日插值
	for (int high = size - 1 , low = 0 ,  mid = 0;  low <= high;
		mid = (high + low) / 2		// 2分查詢法
		//mid = high + (low - high)* 1.0 *( key - arr[high]) / (arr[low] - arr[high])//拉格朗日插值
		)
	{
		count++;
		printf("最大值 %d  最小值 %d  中間值 %d  %d次查詢\n", high, low, mid, count);
		int mindValue = arr[mid];
		if (mindValue == key) 
			return 1;
		else if (mindValue>key) 
			high = mid - 1;
		else 
			low = mid + 1;
	}
	return 0;
}