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

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 
      
        6 #include 
       
         7 #include 
        
          8 #include 
         
           9 #include 
          
           10 #include 
           
            11 #include 
            
             12 #include 
             
              13 #include 
              
               14 #include 
               
                15 #include 
                
                 16 #include 
                 
                  17 #include 
                  
                   18 #include 
                   19 #include 
                    
                     20 #include 
                     
                      21 #include 
                      
                       22 #include 
                       
                        23 #include 
                        
                         24 #include 
                         
                          25 using namespace std;26 #define XINF INT_MAX27 #define INF 0x3FFFFFFF28 #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
                          
                           =L;X--)33 #define CLR(A,X) memset(A,X,sizeof(A))34 #define IT iterator35 typedef long long ll;36 typedef pair
                           
                             PII;37 typedef vector
                            
                              VII;38 typedef vector
                             
                               VI;39 #define MAXN 100001040 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

转载于:https://www.cnblogs.com/fraud/p/4354694.html

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