poj 2503 Trie树

　　典型的Trie树， 算是复习一下字符串吧， 就是输入有点恶心，代码如下：

#include <cstdio>
#include <cstring>
#include <algorithm>using namespace std;
const int maxn = 500000+100;
struct Trie{bool isword;int next[26];char words[15];Trie(){memset(next, -1, sizeof(next));isword = false;}
}Root;
Trie node[maxn];
int n;void Insert(char *tar){Trie *head = &Root;char *s = tar;while(*tar!=' ') tar++;*tar='\0';tar++;while(*tar!='\0'){int id = *tar - 'a';if(head->next[id] == -1){head->next[id] = n++;}head = &node[head->next[id]];tar++;}head->isword = true;//printf("s = %s\n", s);strcpy(head->words, s);
}char *Search(char *tar)
{Trie *head = &Root;while(*tar){int id = *tar - 'a';if(head->next[id] == -1) return NULL;head = &node[head->next[id]];tar++;}if(head->isword) return head->words;else return NULL;
}char str[100];int main(){n = 0;while(gets(str)){bool kongge = false;int len = strlen(str);for(int i=0; i<len; i++) {if(str[i] == ' '){kongge = true;break;}}if(str[0]<'a'||str[0]>'z') continue;if(kongge) Insert(str);else {char *p = Search(str);if(p == NULL) printf("eh\n");else printf("%s\n", p);}}return 0;
}