【练习05】 AC自动机 1001 病毒侵袭

算法思路：AC自动机。

要点：

1.val存储病毒的编号；

2.find函数中当找到一个模板后，应该顺着失配边往回走，由last数组递归判断是否还有其他的子模板能够匹配，所有找到的模板的val值保存到数组save中。

3.对save数组进行sort排序，注意输出格式，依次打印病毒编号。

4.题中要求是“可见字符”，在不超内存的情况下，sigma_size最好开到127。

//模板开始#include <string>   #include <vector>   #include <algorithm>   #include <iostream>   #include <sstream>   #include <fstream>   #include <map>   #include <set>   #include <cstdio>   #include <cmath>   #include <cstdlib>   #include <ctime>#include <iomanip>#include <string.h>#include <queue>#define SZ(x) (int(x.size()))using namespace std;int toInt(string s){istringstream sin(s); int t; sin>>t; return t;}template<class T> string toString(T x){ostringstream sout; sout<<x; return sout.str();}typedef long long int64;int64 toInt64(string s){istringstream sin(s); int64 t; sin>>t;return t;}template<class T> T gcd(T a, T b){ if(a<0) return gcd(-a, b);if(b<0) return gcd(a, -b);return (b == 0)? a : gcd(b, a % b);}//模板结束（通用部分）#define ifs cin#define maxnode 100005#define sigma_size 127int save[maxnode];int cnt;struct Trie{int ch[maxnode][sigma_size];int val[maxnode];int sz;int f[maxnode];int last[maxnode];Trie(){sz = 1;memset(ch[0], 0, sizeof(ch[0]));}int idx(char c){return (int)c;}void insert(char* s, int v){int u = 0, n = strlen(s);for(int i = 0; i < n; i++){int c = idx(s[i]);if(!ch[u][c]){memset(ch[sz], 0, sizeof(ch[sz]));val[sz] = 0;ch[u][c] = sz++;}u = ch[u][c];}val[u] = v;}//int search(char* s, int n)//{//int u = 0;//int flag = 1;//for(int i = 0; i < n; i++)//{//int c = idx(s[i]);//if(ch[u][c] == 0)//{//flag = 0;//break;//}//u = ch[u][c];//}//if(flag && val[u])//{//return 1;//}//else//{//return 0;//}//}void getFail(){queue<int> q;f[0] = 0;for(int c = 0; c < sigma_size; c++){int u = ch[0][c];if(u){f[u] = 0;q.push(u);last[u] = 0;}while(!q.empty()){int r = q.front();q.pop();for(int c = 0; c < sigma_size; c++){int u = ch[r][c];if(!u){continue;}q.push(u);int v = f[r];while(v && !ch[v][c]){v = f[v];}f[u] = ch[v][c];last[u] = val[f[u]] ? f[u] : last[f[u]];}}}}void save_all(int j){if(j){save_all(last[j]);save[cnt++] = val[j];}}void find(char* T){int n = strlen(T);int j = 0; for(int i = 0; i < n; i++){int c = idx(T[i]);while(j && !ch[j][c]) {j = f[j];}j = ch[j][c];if(val[j]){save_all(j);}else{if(last[j]){save_all(last[j]);}}}}};Trie t;char a[505][205];char b[10005];int jishu;//【练习05】 AC自动机 1001 病毒侵袭int main(){//ifstream ifs("shuju.txt", ios::in);int n;while(ifs>>n){for(int i = 1; i <= n; i++){//ifs>>a[i];scanf("%s", &a[i]);t.insert(a[i], i);}t.getFail();ifs>>n;jishu = 0;for(int i = 1; i <= n; i++){//ifs>>b;scanf("%s", &b);cnt = 0;memset(save, 0, sizeof(save));t.find(b);if(!save[0]){continue;}else{jishu++;}sort(save, save + cnt);cout<<"web "<<i<<":";for(int j = 0; j < cnt; j++){cout<<" "<<save[j];}cout<<endl;}cout<<"total: "<<jishu<<endl;}return 0;}