AC自动机模板先存着，还不会...

最新推荐文章于 2024-04-28 22:37:46 发布

原创最新推荐文章于 2024-04-28 22:37:46 发布 · 822 阅读

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CC 4.0 BY-SA版权

本文介绍了一种基于AC自动机的数据结构实现方法，并详细展示了如何通过插入字符串、获取失败指针以及查找模式来完成模式匹配的过程。文章通过具体代码实现了AC自动机的基本操作，并提供了一个简单的例子来演示其使用方式。

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//my first ACAutomaton
# include <set>
# include <map>
# include <list>
# include <queue>
# include <stack>
# include <cmath>
# include <string>
# include <cstdio>
# include <vector>
# include <cstdlib>
# include <cstring>
# include <iostream>
# include <algorithm>

using namespace std ;

# define ll             long long
# define uint           unsigned int
# define ull            unsigned long long
# define PB             push_back
# define SIZE(x)        (int)x.size()
# define clr(x,y)       memset(x,y,sizeof(x))
# define MP(x,y)        make_pair(x,y)
# define read(n)        scanf ( "%d" , & (n) )
# define reads(n)       scanf ( "%s" , n ) ;
# define ALL(t)         (t).begin(),(t).end()
# define FOR(i,n,m)     for ( int i = n ; i <= m ; i ++ )
# define IT             ::iterator
# define vint           vector<int>
# define vstring        vector<string>
# define code(x)        (x-'a')

const ll mod = 1e9+7 ;
const ll LMAX = 1e18 ;
const int MAX = 1e9 ;
const double EPS = 1e-8;

const int MAX_NODE = 500005;
const int CHILD_NUM = 26;

int ans;

class ACAutomaton {
private:
        int chd[MAX_NODE][CHILD_NUM];
        int val[MAX_NODE];
        int fail[MAX_NODE];
        int sz ;
public:
        void init() {
                memset(chd[0] , 0 , sizeof(chd[0]));
                sz = 1;
        }

        void insert(char *s,int key) {
                int p = 0;
                for ( ; *s ; s ++) {
                        int c = code (*s);
                        if (!chd[p][c]) {
                                memset(chd[sz] , 0 , sizeof(chd[sz]));
                                val[sz] = 0;
                                chd[p][c] = sz ++;
                        }
                        p = chd[p][c];
                }
                val[p] += key;   //键值
        }

        void getfail() {
                queue < int > q ;
                for (int i = 0 ; i < CHILD_NUM ; i ++) {
                        if (chd[0][i]) {
                                fail[ chd[0][i] ] = 0;
                                q.push (chd[0][i]);
                        }
                }
                while ( !q.empty() ) {
                        int u = q.front();
                        q.pop();
                        for (int i = 0 ; i < CHILD_NUM ; i ++) {
                                int v = chd[u][i];
                                if (v) {
                                        q.push (v);
                                        int tmp = fail[u];
                                        while (tmp && !chd[tmp][i])  tmp = fail[tmp];
                                        if (chd[tmp][i]) {
                                                tmp = chd[tmp][i];
                                        }
                                        fail[v] = tmp;
                                }
                        }
                }
        }

        void find(char* t) {
                int len = strlen (t) ,p = 0;
                for (int i = 0 ; i < len ; i ++) {
                        int c = code (t[i]);
                        while (p && !chd[p][c]) {
                                p = fail[p];
                        }
                        if (chd[p][c]) {
                                p = chd[p][c];
                                int tmp = p;
                                while (tmp && val[tmp] != -1) {
                                        ans += val[tmp];
                                        val[tmp] = -1;
                                        tmp = fail[tmp];
                                }
                        }
                }
        }
} ac;

char s[55] ,t[1000005];

int main() {
        /*int T;
        read (T);
        while (T--) {
                ac.init();
                ans = 0;
                int n;
                read (n);
                while (n--) {
                        reads (s);
                        ac.insert(s,1);
                }
                ac.getfail();
                reads (t);
                ac.find(t);
                cout << ans << endl ;
        }
        */
        int a,b;
        read(a),read(b);
        cout << a + b << endl ;
}