[算法天天练]递归查找和非递归查找

//Data为要查找的数组，x为待查找数据值，beg为查找范围起始，last为查找范围终止

//非递归法
int BiSearch(int data[], const int x, int beg, int last)
{
	int mid;//中间位置
	if (beg > last)
	{
		return -1;
	}

	while(beg <= last)
	{
		mid = (beg + last) / 2;
		if (x == data[mid] )
		{
			return mid;
		}
		else if (data[mid] < x)
		{
			beg = mid + 1;
		}
		else if (data[mid] > x)
		{
			last = mid - 1;
		}
	}
	return -1;
}

//递归法
int IterBiSearch(int data[], const int x, int beg, int last)
{
	int mid = -1;
	mid = (beg + last) / 2;
	if (x == data[mid])
	{
		return mid;
	}
	else if (x < data[mid])
	{
		return IterBiSearch(data, x, beg, mid - 1);
	}
	else if (x > data[mid])
	{
		return IterBiSearch(data, x, mid + 1, last);
	}
	return -1;
}

//主函数
int _tmain(int argc, _TCHAR* argv[])
{
	int data1[60] = {0};
	int no2search = 45;

	cout << "The array is : " << endl;
	int siz = sizeof(data1)/sizeof(int);
	for (int i = 0; i < siz; i++)
	{
		data1[i] = i;
		cout << data1[i] << " ";
	}
	cout << endl;

	int index = -1;
	//index = BiSearch(data1, no2search, 0, siz);
	index = IterBiSearch(data1, no2search, 0, siz);
	cout << "Index of " << no2search << " is " << index << endl;

	getchar();
	return 0;
}