二分法查找数组a

// Project25.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include <iostream>

define size 5

using namespace std;

int main()
{
int i, j;
float t, a[size];

//从键盘上为数组赋值
for (i = 0; i < size; i++)
{
	cout << "a[" << i << "]=";
	cin >> a[i];
}

//对数组按从小到大顺序排序
for (i = 0; i < size - 1; i++)
{
	for (j = i + 1; j < size; j++)
	{
		if (a[i] > a[j])
		{
			t = a[i];
			a[i] = a[j];
			a[j] = t;
		}
	}
}
//显示排序结果
for (i = 0; i < size; i++)
{
	cout << a[i] << "  ";
	cout << endl;
}


//输入要查找的数据
int value;
int found;//找到为1,否则为0
int low, high, mid;
for (i = 1; i <= 3; i++)
{
	cout << "value = ";
	cin >> value;

	//二分法查找数组a
	found = 0;
	low = 0;
	high = size - 1;
	while (low <= high)
	{
		mid = (high + low) / 2;
		if (a[mid] == value)
		{
			found = 1;
			break;
		}
		if (a[mid] < value)
		{
			low = mid + 1;
		}
		else
		{
			high = mid - 1;
		}
	}
	if (found)
		cout << "This value found at :a[" << mid << "]=" << a[mid] << endl;
	else
		cout << "The " << value << " is not found!" << endl;

}

return 0;

}

posted @ 2021-07-05 14:43  江南王小帅  阅读(77)  评论(0)    收藏  举报