Codeforces 652B z-sort（水题）

http://codeforces.com/contest/652/problem/B

B. z-sort

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

A student of z-school found a kind of sorting called z-sort. The array a with n elements are z-sorted if two conditions hold:

1. ai ≥ ai - 1 for all even i,
2. ai ≤ ai - 1 for all odd i > 1.

For example the arrays [1,2,1,2] and [1,1,1,1] are z-sorted while the array [1,2,3,4] isn’t z-sorted.

Can you make the array z-sorted?

Input

The first line contains a single integer n (1 ≤ n ≤ 1000) — the number of elements in the array a.

The second line contains n integers ai (1 ≤ ai ≤ 109) — the elements of the array a.

Output

If it's possible to make the array a z-sorted print n space separated integers ai — the elements after z-sort. Otherwise print the only word "Impossible".

Examples

input

41 2 2 1

output

1 2 1 2

input

51 3 2 2 5

output

1 5 2 3 2

232

题意：

定义的 z 序列为，第偶数项大于其前一项，奇数项小于其前一项，输出由给定的数组元素构成的z 序列。

思路：

数组有序后，

引入两个变量，奇数项的由1 到n输出，偶数项的由 n到 1 输出即可。

AC CODE：

#include<stdio.h>#include<cstring>#include<cmath>#include<algorithm>#define HardBoy main()#define ForMyLove return 0;using namespace std;const int MYDD = 1103;int HardBoy {int n, a[MYDD];scanf("%d", &n);for(int j = 1; j <= n; j++)scanf("%d", &a[j]);sort(a+1, a+1+n);int even = n, odd = 1, T = 1;while(T <= n){if(T % 2){printf("%d ", a[odd++]);} else {printf("%d ", a[even--]);}T++;}ForMyLove}