题目链接：http://hihocoder.com/problemset/problem/1036
不知道为什么匹配到某点存在next[idx]的时候，只需要检查这一个sign就行，如果检查此点的fail的sign就会TLE。
大概数据比较弱能让我水过吧。
1 #include <bits/stdc++.h> 2 using namespace std; 3 4 typedef struct Node { 5 Node* fail; 6 Node* next[26]; 7 bool sign; 8 Node() { fail = NULL; for(int i = 0; i < 26; i++) next[i] = NULL; } 9 }Node; 10 11 const int maxn = 1000100; 12 Node* rt; 13 int n; 14 char tmp[maxn]; 15 16 void insert(Node* rt, char* str) { 17 Node* tmp = rt; 18 for(int i = 0; str[i]; i++) { 19 int idx = str[i] - 'a'; 20 if(tmp->next[idx] == NULL) tmp->next[idx] = new Node(); 21 tmp = tmp->next[idx]; 22 } 23 tmp->sign = 1; 24 } 25 26 void build(Node* rt) { 27 Node* cur; 28 Node* tmp; 29 queue<Node*> q; 30 q.push(rt); 31 while(!q.empty()) { 32 cur = q.front(); q.pop(); 33 for(int i = 0; i < 26; i++) { 34 if(!cur->next[i]) continue; 35 if(cur == rt) cur->next[i]->fail = rt; 36 else { 37 tmp = cur->fail; 38 do { 39 if(tmp->next[i]) { 40 cur->next[i]->fail = tmp->next[i]; 41 break; 42 } 43 } while(tmp = tmp->fail); 44 if(tmp == NULL) cur->next[i]->fail = rt; 45 } 46 q.push(cur->next[i]); 47 } 48 } 49 } 50 51 bool query(Node* rt, char* str) { 52 Node* cur = rt; 53 for(int i = 0; str[i]; i++) { 54 int idx = str[i] - 'a'; 55 while(cur->next[idx] == NULL && cur != rt) cur = cur->fail; 56 cur = cur->next[idx]; 57 if(cur == NULL) { 58 cur = rt; 59 continue; 60 } 61 if(cur->sign) return 1; 62 } 63 return 0; 64 } 65 66 int main() { 67 // freopen("in", "r", stdin); 68 while(~scanf("%d", &n)) { 69 rt = new Node(); 70 for(int i = 0; i < n; i++) { 71 scanf("%s", tmp); 72 insert(rt, tmp); 73 } 74 build(rt); 75 scanf("%s", tmp); 76 if(query(rt, tmp)) puts("YES"); 77 else puts("NO"); 78 } 79 return 0; 80 }