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 ≤ 10 ⁶), 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

 1 //#####################

 2 //Author:fraud

 3 //Blog: http://www.cnblogs.com/fraud/

 4 //#####################

 5 #include <iostream>

 6 #include <sstream>

 7 #include <ios>

 8 #include <iomanip>

 9 #include <functional>

10 #include <algorithm>

11 #include <vector>

12 #include <string>

13 #include <list>

14 #include <queue>

15 #include <deque>

16 #include <stack>

17 #include <set>

18 #include <map>

19 #include <cstdio>

20 #include <cstdlib>

21 #include <cmath>

22 #include <cstring>

23 #include <climits>

24 #include <cctype>

25 using namespace std;

26 #define XINF INT_MAX

27 #define INF 0x3FFFFFFF

28 #define MP(X,Y) make_pair(X,Y)

29 #define PB(X) push_back(X)

30 #define REP(X,N) for(int X=0;X<N;X++)

31 #define REP2(X,L,R) for(int X=L;X<=R;X++)

32 #define DEP(X,R,L) for(int X=R;X>=L;X--)

33 #define CLR(A,X) memset(A,X,sizeof(A))

34 #define IT iterator

35 typedef long long ll;

36 typedef pair<int,int> PII;

37 typedef vector<PII> VII;

38 typedef vector<int> VI;

39 #define MAXN 1000010

40 int a[MAXN];

41 int main()

42 {

43     int n;

44     while(scanf("%d",&n)&&n){

45          a[1]=3;

46          a[2]=1;

47          for(int i=3;i<=n;i++){

48              if(i&1)a[i]=i+2;

49              else a[i]=i-2;

50          }

51          if(n&1)a[n]=n-1;

52          else{

53              a[n]=n-2;

54              a[n-1]=n;

55          }

56          printf("%d",a[1]);

57          for(int i=2;i<=n;i++){

58              printf(" %d",a[i]);

59          }

60          printf("\n");

61     }

62     return 0;

63 }

代码君