#include <stdio.h>
#define maxSize 100
#define num 4
int R[maxSize] = { 0 };
int count = 0;
/*********輸入資料*********/
void Indata()
{
	printf("請輸入整數資料(按回車鍵停止輸入):");
	int i = 0;
	char ch;
	while (1)
	{
		scanf_s("%d", &R[i]);
		i++;
		count++;
		ch = getchar();
		if ('\n' == ch)
			break;
	}
}
/*******順序查詢*******/
int Search_Seq(int r[],int n)
{
	int i=0;
	int key;
	printf("請輸入您要查詢的數值:");
	scanf_s("%d", &key);
	printf("順序查詢:\n");
	while (r[i] != key)
		i++;
	if (i < n)
	{
		printf("位置:%d 數值:%d", i, r[i]);
		return i;
	}
	else
	{
		printf("查詢無該值");
		return -1;
	}	
}

/***********折半查詢*********/
//僅適用於有序的順序表
int Binary_Search(int r[],int low,int high)
{
	int mid;
	int key;
	printf("請輸入您要查詢的數值:");
	scanf_s("%d", &key);
	printf("折半查詢:\n");
	while (low <= high)
	{
		mid = (low + high) / 2;
		if (r[mid] == key)
		{
			printf("位置:%d 數值:%d", mid, r[mid]);
			return mid;
		}		
		else if (r[mid] > key)
			high = mid - 1;     //從前半部分繼續查詢
		else
			low = mid + 1;     //從後半部分開始查詢	
	}
	printf("查詢無該值");
	return -1;
}

void main()
{
	Indata();
	//Search_Seq(R, count);
	printf("\n");
	Binary_Search(R,0, count - 1);
	system("pause");
}