hdu 3065病毒侵袭持续中（ac自动机）

Posted 2020-08-20 Gealo

题目链接 http://acm.hdu.edu.cn/showproblem.php?pid=3065

中文题题意不解释了。

依旧稍微改一下ac自动机模版就能过了。还有一个坑点！是多组数据！！！

 

#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
using namespace std;
const int M = 5e4 + 10 , MM = 2e6 + 10 , N = 1e3 + 10;
char str[N][60] , sl[MM];
int Next[M][27] , fail[M] , End[M] , c[M / 10] , L , root , cnt , ans;
int newnode() {
    for(int i = 0 ; i <= 26 ; i++) {
        Next[L][i] = -1;
    }
    End[L++] = 0;
    return L - 1;
}
void init() {
    L = 0 , ans = 0;
    root = newnode();
    memset(c , 0 , sizeof(c));
}
void build(char s[]) {
    int len = strlen(s);
    int now = root;
    for(int i = 0 ; i < len ; i++) {
        int id = s[i] - ‘A‘;
        if(Next[now][id] == -1) {
            Next[now][id] = newnode();
        }
        now = Next[now][id];
    }
    End[now] = ++ans;
}
void get_fail() {
    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]);
            }
        }
    }
}
void match(char s[]) {
    int len = strlen(s);
    int now = root;
    for(int i = 0 ; i < len ; i++) {
        int id;
        if(s[i] <= ‘Z‘ && s[i] >= ‘A‘) {
            id = s[i] - ‘A‘;
        }
        else {
            id = 26;
        }
        now = Next[now][id];
        int tmp = now;
        while(tmp != root) {
            if(End[tmp] > 0) {
                c[End[tmp]]++;
            }
            tmp = fail[tmp];
        }
    }
}
int main()
{
    int n;
    while(scanf("%d" , &n) != EOF) {
        init();
        for(int i = 0 ; i < n ; i++) {
            scanf("%s" , str[i + 1]);
            build(str[i + 1]);
        }
        getchar();
        get_fail();
        gets(sl);
        match(sl);
        for(int i = 0 ; i < n ; i++) {
            if(c[i + 1] != 0) {
                printf("%s: %d\n" , str[i + 1] , c[i + 1]);
            }
        }
    }
    return 0;
}