How many - HDU 2609 （trie+最小表示）

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<stdlib.h>
using namespace std;

const int MAXM = 2;
const int MAXN = 1007;

struct node
{
    node *next[MAXM];
};

bool BuildTrie(node *head, char s[])
{///建立字典树，如果s已经存在返回0，否则返回1
    node *p = head;
    bool newNode = false;

    for(int i=0; s[i]; i++)
    {
        int k = s[i]-‘0‘;

        if(p->next[k] == NULL)
        {
            newNode = true;
            p->next[k] = new node();
        }
        p = p->next[k];
    }

    return newNode;
}
void FreeTrie(node *head)
{
    node *p = head;

    for(int i=0; i<MAXM; i++)
    {
        if(p->next[i] != NULL)
            FreeTrie(p->next[i]);
    }

    free(p);
}
int GetMinOrder(char s[], int N)
{///求出来最小表示的首位置
    int i=0, j=1;

    while(i<N && j<N)
    {
        int k=0;

        while(s[i+k] == s[j+k] && k<N)
            k++;

        if(k == N)break;

        if(s[i+k] < s[j+k])
        {
            if(j+k > i)
                j = j+k+1;
            else
                j = i+1;
        }
        else
        {
            if(i+k > j)
                i = i+k+1;
            else
                i = j+1;
        }
    }

    return min(i, j);
}

int main()
{
    int N;

    while(scanf("%d", &N) != EOF)
    {
        char s[MAXN]={0}, p[MAXN];
        node *head = new node();
        int ans = 0, len=0;

        while(N--)
        {
            scanf("%s", p);
            if(!len)len = strlen(p);

            strcpy(s, p);
            strcat(s, p);

            int MinIndex = GetMinOrder(s, len);
            strncpy(p, s+MinIndex, len);///把这个串转换成它的最小表示

            ans += BuildTrie(head, p);
        }

        printf("%d\n", ans);

        FreeTrie(head);
    }

    return 0;
}