hdu 1671

Trie树，题目不难，但还是WA了一次，没有考虑后输入的字符串是前输入的字符串的前缀的情况，真是太粗心了。不过做了几道Trie树的题目以后，代码写得还是比较通用了，慢慢再改进吧

/*
 * hdu1671/win.c
 * Created on: 2011-8-19
 * Author    : ben
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define CHAR_NUM 10
#define BASE '0'

typedef struct Trie {
    unsigned char isaend;
    struct Trie * br[CHAR_NUM];
} Trie;

int flag;

Trie* newTrieNode() {
    int i;
    Trie* node = (Trie *) malloc(sizeof(Trie));
    for (i = 0; i < CHAR_NUM; i++) {
        node->br[i] = NULL;
    }
    node->isaend = 0;
    return node;
}

void insert(Trie *root, char *str, int len) {
    int i;
    if (root->isaend) {
        flag = 0;
    }
    if (len <= 0) {
        root->isaend = 1;
        for (i = 0; i < CHAR_NUM; i++) {
            if(root->br[i]) {
                flag = 0;
                return ;
            }
        }
        return;
    }
    i = (*str) - BASE;
    if (!root->br[i]) {
        root->br[i] = newTrieNode();
    }
    insert(root->br[i], str + 1, len - 1);
}

void destroy(Trie *root) {
    int i;
    for (i = 0; i < CHAR_NUM; i++) {
        if (root->br[i] != NULL) {
            destroy(root->br[i]);
        }
    }
    free(root);
}

void work() {
    Trie *root = newTrieNode();
    int n;
    char str[100];
    scanf("%d", &n);
    flag = 1;
    while (n--) {
        scanf("%s", str);
        insert(root, str, strlen(str));
    }
    if (flag) {
        puts("YES");
    } else {
        puts("NO");
    }
    destroy(root);
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    int T;
    scanf("%d", &T);
    while (T--) {
        work();
    }
    return 0;
}