[作业]折半查找

[作业]折半查找

#include "stdio.h"
#define MAX_ARR 100
#define LEN		10

typedef struct
{
	int r[MAX_ARR];
	int length;
}Table;

void CreatTable_Sq(Table &t)
{
	int a = 2;
	t.length = 0;
	int i;
	for(i=0;i<LEN;i++)
	{
		t.r[t.length] = a;
		t.length++;
		a += 2;
	}
}

int search_bin(Table t, int key)
{
	int low, high, mid;
	low = 1; high = t.length;
	while (low <= high)
	{
		mid = (low + high) / 2;
		if (key == t.r[mid]) 
			return mid;		//key在low与high中间，直接返回中间的数字
		else if (key<t.r[mid]) 
			high = mid - 1;	//key<mid,high到mid前,low不动
		else 
			low = mid + 1;	//key<mid,low到mid后,high不动
	}
	return 0;
}

int main()
{
	Table t;
	int key, c;
	CreatTable_Sq(t);
	printf("数组为：\n");
	for (int i = 0; i < LEN; i++)
		printf("%d\t",t.r[i]);
	printf("\n请输入要查找的数字\n");
	scanf("%d", &key);
	c = search_bin(t, key);
	printf("\n数字 %d 在 %d 位置\n\n", key, c + 1);
	return 0;
}