学步园

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#include <stdio.h>
#include <string.h>
#include <stdlib.h>

const int N = 100005;
const int M = 10;
const int mod = 100003;

int head[N], num, a[M], snow[N][M];

struct node
{
    int pos, next;
}e[N];

void hash(int val, int pos)
{
    e[num].pos = pos;
    e[num].next = head[val];
    head[val] = num++;
}
int check(int a, int b)
{
    int i, j;
    for(i=0; i<6; ++i)
    {
        j=0;
        while(j<6&&snow[a][(i+j)%6]==snow[b][j])
            j++;
        if(j==6)
            return 1;
        j=0;
        while(j<6&&snow[a][5-(i+j)%6]==snow[b][j])
            j++;
        if(j==6)
            return 1;
    }
    return 0;
}
int readint()
{
    int res=0,ch;
    while(!((ch=getchar())>='0'&&ch<='9'))
    {
       if(ch==EOF)  return 1<<30;
    }
    res=ch-'0';
    while((ch=getchar())>='0'&&ch<='9')
        res=res*10+(ch-'0');
    return res ;
}

int find(int n)
{
    int i, j, val, pos;
    val = ((snow[n][0]+snow[n][2]+snow[n][4])^(snow[n][1]+snow[n][3]+snow[n][5]) )% mod;
    for(i=head[val]; ~i; i=e[i].next)
    {
        pos =e[i].pos;
        if(check(n, pos))
            return 1;
    }
    hash(val, n);
    return 0;
}

int main()
{
    int i, j, n, val, pos, flag;
    while(~scanf("%d", &n))
    {
        flag = 0;
        num = 0;
        memset(head, -1, sizeof head );
        for(i=1; i<=n; ++i)
        {
            for(j=0; j<6; ++j)
                snow[i][j] = readint();
            if(flag)
                continue;
            if(find(i))
                flag = 1;
        }

        if(flag)
            printf("Twin snowflakes found.\n");
        else
            printf("No two snowflakes are alike.\n");
    }
    return 0;
}