poj 3349 Snowflake Snow

数据太大，为了增加查找的效率，直接用hash来进行处理，其实就是一个2维的表。

#include<cstdio>#include<cstring>#include<iostream>#include<cstdlib>#define MOD 10001using namespace std;int n;typedef struct node{int arm[6];struct node *next;}Node;Node  arr[MOD];void ini(){    for(int i=0; i<MOD; ++i)      {        arr[i].next = NULL;      }}bool judge(Node a,Node b){    for(int i=0; i<6; ++i)     if(a.arm[0]==b.arm[i])    {        int j;        for(j = 1; j < 6; ++j)         if(a.arm[j] != b.arm[(i+j)%6])            break;          if(j==6)          return true;        for(j = 1; j < 6; ++j)         if(a.arm[6-j] != b.arm[(i+j)%6])            break;        if(j==6)        return true;    }    return false;}int main(void){    cin>>n;    ini();    bool flag = false;    for(int i = 1; i <= n; ++i)    {      Node now,next;      int sum = 0;      for(int j = 0; j < 6; ++ j)      {         scanf("%d",&now.arm[j]);         sum += now.arm[j];      }         int hash = sum % MOD;         Node * point = arr[hash].next;         if(!flag)         {          while(point)          {           if(judge(*point,now))           {            flag = true;            break;           }           point = point->next;          }         point = &arr[hash];         Node *tmp = (Node *)malloc(sizeof(Node));         *tmp = now;         tmp->next = point->next;         point->next = tmp;         }      }        if(flag)          printf("Twin snowflakes found.\n");        else          printf("No two snowflakes are alike.\n");      return 0;}