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;
}