二分法的五种功能的实现

[c++]代码库

void whilee1(int *a,int shang,int xia,int num)//
{
	cout << "shang\tzhong\txia\t " << endl;
	while (shang >=xia)//如果把序号大的看作上面用shang > xia,序号小的看作上面用xia<shang
	{
		int zhong = (shang + xia) / 2;
		cout << shang << "\t" << zhong << "\t" << xia << endl;
		if (num == a[zhong])
		{
			cout << "whilee1 find" << endl;
			break;
		}
		else if (a[zhong]<num)
		{
			xia = zhong + 1;

		}
		else  //(num<zhong)
		{
			shang = zhong - 1;
		}

	}
	if (xia >shang)
	{	
		cout << "while1 not find " << endl;
	}
}

[代码运行效果截图]

[源代码打包下载]