Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 131072/131072 K (Java/Others)
Total Submission(s): 67122 Accepted Submission(s): 22584
#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <iomanip>
#include <math.h>
#include <map>
using namespace std;
#define FIN freopen("input.txt","r",stdin);
#define FOUT freopen("output.txt","w",stdout);
#define INFLL 0x3f3f3f3f3f3f3f
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
typedef long long LL;
typedef pair<double, double> PII;
struct Trie {
int next[500010][26], fail[500010], end[500010];
int root, L;
int newnode() {
for(int i = 0; i < 26; i++)
next[L][i] = -1;
end[L++] = 0;
return L - 1;
}
void init() {
L = 0;
root = newnode();
}
void insert(char buf[]) {
int len = strlen(buf);
int now = root;
for(int i = 0; i < len; i++) {
if(next[now][buf[i] - ‘a‘] == -1)
next[now][buf[i] - ‘a‘] = newnode();
now = next[now][buf[i] - ‘a‘];
}
end[now]++;
}
void build() {
queue<int>Q;
fail[root] = root;
for(int i = 0; i < 26; i++)
if(next[root][i] == -1)
next[root][i] = root;
else {
fail[next[root][i]] = root;
Q.push(next[root][i]);
}
while( !Q.empty() ) {
int now = Q.front();
Q.pop();
for(int i = 0; i < 26; i++)
if(next[now][i] == -1)
next[now][i] = next[fail[now]][i];
else {
fail[next[now][i]] = next[fail[now]][i];
Q.push(next[now][i]);
}
}
}
int query(char buf[]) {
int len = strlen(buf);
int now = root;
int res = 0;
for(int i = 0; i < len; i++) {
now = next[now][buf[i] - ‘a‘];
int temp = now;
while( temp != root ) {
res += end[temp];
end[temp] = 0;
temp = fail[temp];
}
}
return res;
}
void debug() {
for(int i = 0; i < L; i++) {
printf("id = %3d,fail = %3d,end = %3d,chi = [", i, fail[i], end[i]);
for(int j = 0; j < 26; j++)
printf("%2d", next[i][j]);
printf("]\n");
}
}
};
Trie AC;
char s[1000005];
int main() {
//FIN
int T;
scanf("%d", &T);
while(T--) {
AC.init();
int n;
scanf("%d", &n);
for(int i = 1; i <= n; i++) {
scanf("%s", s);
AC.insert(s);
}
AC.build();
scanf("%s", s);
printf("%d\n", AC.query(s));
}
return 0;
}
HDU 2222 Keywords Search AC自动机
原文:http://www.cnblogs.com/Hyouka/p/7450827.html