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 
     
       #include 
      
        #include 
       
         #include 
        
          #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; }