uva11630 or hdu2987 Cyclic antimonotonic permutations(构造水题)

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Cyclic antimonotonic permutations

Time Limit: 20000/5000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)

Problem Description

A permutation is a sequence of integers which contains each integer from 1 to n exactly once. In this problem we are looking for permutations with special properties:

1. Antimonotonic: for each consecutive 3 values p_i-1, p_i, p_i+1 (1 < i < n), p_i should either be the smallest or the biggest of the three values. 
2. Cyclic: The permutation should consist of only one cycle, that is, when we use p_i as a pointer from i to p_i, it should be possible to start at position 1 and follow the pointers and reach all n positions before returning to position 1. 

 

Input

The input file contains several test cases. Each test case consists of a line containing an integer n, (3 ≤ n ≤ 10⁶), the number of integers in the permutation. Input is terminated by n=0.

 

Output

For each test case print a permutation of the integers 1 to n which is both antimonotonic and cyclic. In case there are multiple solutions, you may print any one. Separate all integers by whitespace characters.

 

Sample Input

3
5
10
0

 

Sample Output

3 1 2
4 5 2 3 1
6 10 2 9 3 5 4 7 1 8

 

Source

2009/2010 Ulm Local Contest

分奇数和偶数，随便搞一下

hdu由于没有special judge，无法AC

 //#####################
 //Author:fraud
 //Blog: http://www.cnblogs.com/fraud/
 //#####################
 #include <iostream>
 #include <sstream>
 #include <ios>
 #include <iomanip>
 #include <functional>
 #include <algorithm>
 #include <vector>
 #include <string>
 #include <list>
 #include <queue>
 #include <deque>
 #include <stack>
 #include <set>
 #include <map>
 #include <cstdio>
 #include <cstdlib>
 #include <cmath>
 #include <cstring>
 #include <climits>
 #include <cctype>
 using namespace std;
 #define XINF INT_MAX
 #define INF 0x3FFFFFFF
 #define MP(X,Y) make_pair(X,Y)
 #define PB(X) push_back(X)
 #define REP(X,N) for(int X=0;X<N;X++)
 #define REP2(X,L,R) for(int X=L;X<=R;X++)
 #define DEP(X,R,L) for(int X=R;X>=L;X--)
 #define CLR(A,X) memset(A,X,sizeof(A))
 #define IT iterator
 typedef long long ll;
 typedef pair<int,int> PII;
 typedef vector<PII> VII;
 typedef vector<int> VI;
 #define MAXN 1000010
 int a[MAXN];
 int main()
 {
     int n;
     while(scanf("%d",&n)&&n){
          a[]=;
          a[]=;
          for(int i=;i<=n;i++){
              if(i&)a[i]=i+;
              else a[i]=i-;
          }
          if(n&)a[n]=n-;
          else{
              a[n]=n-;
              a[n-]=n;
          }
          printf("%d",a[]);
          for(int i=;i<=n;i++){
              printf(" %d",a[i]);
          }
          printf("\n");
     }
     return ;
 }

代码君