思维题,想到就秒杀,没想到或者想错方向了那么就完蛋了
0 1 2 3 4
1 2 3 4 0
你就会发现是可以的。
我经历了很久错误的思维,找到了一些性质
1. ai+bi的和一定为一串从(n/2)递增的序列, 因为所有ai+bi(i从0-n-1)的和为一个固定的数,而得到的ci又要是0-n-1各一次。 所以也同时说明偶数的情况是不可行的。
然后稍加组合就可以发现将两个 0-n-1 的序列错开相加就可以得到结果。。
Bike is interested in permutations. A permutation of length n is an integer sequence such that each integer from 0 to (n - 1) appears exactly once in it. For example, [0, 2, 1] is a permutation of length 3 while both [0, 2, 2] and [1, 2, 3] is not.
A permutation triple of permutations of length n (a, b, c) is called a Lucky Permutation Triple if and only if . The sign ai denotes the i-th element of permutation a. The modular equality described above denotes that the remainders after dividing ai + bi by n and dividing ci by n are equal.
Now, he has an integer n and wants to find a Lucky Permutation Triple. Could you please help him?
The first line contains a single integer n (1 ≤ n ≤ 105).
If no Lucky Permutation Triple of length n exists print -1.
Otherwise, you need to print three lines. Each line contains n space-seperated integers. The first line must contain permutation a, the second line — permutation b, the third — permutation c.
If there are multiple solutions, print any of them.
5
1 4 3 2 0
1 0 2 4 3
2 4 0 1 3
2
-1
In Sample 1, the permutation triple ([1, 4, 3, 2, 0], [1, 0, 2, 4, 3], [2, 4, 0, 1, 3]) is Lucky Permutation Triple, as following holds:
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In Sample 2, you can easily notice that no lucky permutation triple exists.
#include <iostream> #include <stdio.h> #include <string.h> using namespace std; int g[100100]; int g1[100100]; int main() { int n; scanf("%d",&n); if(n%2==0) printf("-1"); else { int cnt=0; for(int i=n/2;i<n;i++) g[cnt++]=i; for(int i=0;i<n/2;i++) g[cnt++]=i; for(int i=0;i<n;i++) g1[i]=(g[i]+i)%n; for(int i=0;i<n;i++) printf("%d ",i); printf("\n"); for(int i=0;i<n;i++) printf("%d ",g[i]); printf("\n"); for(int i=0;i<n;i++) printf("%d ",g1[i]); } return 0; }