学步园

用hash链地址法，取了个99997大素数就AC了

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
using namespace std;
const int mod = 99997;
struct node
{
    int len[6];
}f[100010];
vector <int>hash[100000];
int size[100000];
int get_key(node t)
{
    int key = 0;
    for(int i=0;i<6;i++)
        key += t.len[i]%mod;
    return key%mod;
}
bool exit(node t,int key)
{
    int len = size[key];
    if(len == 0)return false;
    for(int i=0;i<len;i++)
    {
        int r = hash[key][i];
        for(int j=0;j<6;j++)
        {
            int flag = 1;
            for(int k=j,cnt = 0;cnt<6;(k = (k==5) ? 0 : k+1),cnt++)
            {
                if(t.len[k] != f[r].len[cnt]){flag = 0;break;}
            }
            if(flag)return true;
        }
        for(int j=0;j<6;j++)
        {
            int flag = 1;
            for(int k=j,cnt = 0;cnt<6;(k = (k==0) ? 5 : k-1),cnt++)
            {
                if(t.len[k] != f[r].len[cnt]){flag = 0;break;}
            }
            if(flag)return true;
        }

    }
    return false;
}
int n;
int main()
{
    //freopen("input.txt","r",stdin);
    while(~scanf("%d",&n))
    {
        for(int i=0;i<100000;i++)
            hash[i].clear();
        memset(size,0,sizeof(size));
        int found = 0;
        for(int i=1;i<=n;i++)
        {
            for(int j=0;j<6;j++)
                scanf("%d",&f[i].len[j]);
            if(found)continue;
            int key = get_key(f[i]);
            if(!exit(f[i],key))hash[key].push_back(i),size[key]++;
            else found = 1;
        }
        //cout << "KK" << endl;
        if(found)printf("Twin snowflakes found.\n");
        else printf("No two snowflakes are alike.\n");

    }
    return 0;
}