2014 网选 5007 Post Robot（暴力或者AC_自动机（有点小题大作了））

//暴力，从每一行的开始处开始寻找要查询的字符
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;

char str[100005];

int main(){
    while(gets(str)){
        for(int i=0; str[i]; ++i)
            if(str[i]=='A'){
                if(strstr(str+i, "Apple") == str+i)
                    printf("MAI MAI MAI!\n");
            }
            else if(str[i]=='i'){
                if(strstr(str+i, "iPhone") == str+i || strstr(str+i, "iPod") == str+i || strstr(str+i, "iPad") == str+i)
                    printf("MAI MAI MAI!\n");
            }
            else if(str[i]=='S')
                if(strstr(str+i, "Sony") == str+i)
                    printf("SONY DAFA IS GOOD!\n");
    }
    return 0;
} 

 1 //将要匹配的字符串（也就是题目中查询文本中出现的5个单词）建立trie树，然后生成AC_自动机.....
 2 #include<iostream>
 3 #include<cstring>
 4 #include<queue>
 5 #include<cstdio>
 6 #include<algorithm>
 7 using namespace std;
 8 
 9 int trie[30][200];
10 int vis[30], fail[6000];//vis标记的是单词的末尾字符所在的节点
11 char str[][10] = {"Apple", "iPhone", "iPod", "iPad", "Sony"};
12 int cnt;
13 void buildT(){
14     for(int i=0; i<5; ++i){
15         int u=0;
16         for(int j=0; str[i][j]; ++j){
17             if(trie[u][str[i][j]] == 0)
18                 trie[u][str[i][j]] = ++cnt;
19             u=trie[u][str[i][j]];
20         }
21         vis[u]=1;
22     }
23 }
24 
25 void getFail(){
26     queue<int>q;
27     for(int i=0; i<200; ++i)
28         if(trie[0][i]) q.push(trie[0][i]);
29     while(!q.empty()){
30         int u = q.front();
31         q.pop();
32         int v;
33         for(int i=0; i<200; ++i)
34             if(v = trie[u][i]){
35                 fail[v] = trie[fail[u]][i];
36                 q.push(v);
37             }
38             else
39                 trie[u][i] = trie[fail[u]][i];
40     }
41 }
42 
43 void getText(char *ch){
44     int u=0;
45     for(int i=0; ch[i]; ++i){
46         int v = trie[u][ch[i]];
47         u=v;
48         while(v){
49             if(vis[v] && (ch[i]=='d' || ch[i]=='e'))
50                 printf("MAI MAI MAI!\n");
51             else if(vis[v] && ch[i]=='y')
52                 printf("SONY DAFA IS GOOD!\n"); 
53             v = fail[v];
54         }
55     }
56 }
57 
58 char text[10000];
59 
60 int main(){
61     buildT();
62     getFail();
63     while(gets(text)){
64         getText(text);
65     }
66     return 0;
67 }