import java.util.Scanner;

public class p1157 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		while (sc.hasNext()) {
			int n = sc.nextInt();
			if(n==0){
				return;
			}
			int[] a = new int[n];
			for (int i = 0; i < a.length; i++) {
				a[i] = sc.nextInt();
			}
			mySort(a);
			System.out.println(a[a.length / 2]);
		}
	}

	public static void mySort(int[] a) {// 快排
		for (int i = 0; i < a.length - 1; i++) {
			int temp = i;
			for (int j = i + 1; j < a.length; j++) {
				if (a[temp] > a[j]) {
					temp = j;// 记下最小的数
				}
			}
			if (temp != i) {
				a[temp] = a[temp] ^ a[i];
				a[i] = a[temp] ^ a[i];
				a[temp] = a[temp] ^ a[i];
			}
		}
	}
}

首先：是无限输入，当输入零时结束（通过观看c代码总结出，非题意所给）

目标：求出输入母羊数的中间数（N是奇数）

方法：对输入的数据进行*快排*（其他的排序也行,但是不要超时）

Who‘s in the Middle

5
2
4
1
3
5

3

Hint
 
INPUT DETAILS: 

Five cows with milk outputs of 1..5 

OUTPUT DETAILS: 

1 and 2 are below 3; 4 and 5 are above 3.
 

Who's in the Middle

原文：http://blog.csdn.net/hncu1306602liuqiang/article/details/46287875