Cod sursa(job #2810330)

Utilizator buzu.tudor67Tudor Buzu buzu.tudor67 Data 29 noiembrie 2021 00:52:16
Problema Aho-Corasick Scor 95
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 3.54 kb
#include <bits/stdc++.h>
using namespace std;

class Trie{
private:
    static const int ALPHABET_SIZE = 26;
    static const int FIRST_ELEM = 'a';
    int matchCount;
    Trie* suffixLink;
    vector<Trie*> reverseSuffixLinks;
    vector<Trie*> children;
    vector<int> wordIndices;

    void collectMatchCounts(Trie* node, vector<int>& counts){
        for(Trie* nextNode: node->reverseSuffixLinks){
            collectMatchCounts(nextNode, counts);
            node->matchCount += nextNode->matchCount;
        }
        for(int wordIdx: node->wordIndices){
            counts[wordIdx] += node->matchCount;
        }
    }

public:
    Trie(){
        matchCount = 0;
        suffixLink = NULL;
        children.assign(ALPHABET_SIZE, NULL);
    }

    void insert(const string& WORD, const int& WORD_IDX){
        Trie* node = this;
        for(char c: WORD){
            int edgeID = c - FIRST_ELEM;
            if(node->children[edgeID] == NULL){
                node->children[edgeID] = new Trie();
            }
            node = node->children[edgeID];
        }
        node->wordIndices.push_back(WORD_IDX);
    }

    void createSuffixLinks(){
        Trie* root = this;

        queue<Trie*> q;
        for(int edgeID = 0; edgeID < ALPHABET_SIZE; ++edgeID){
            if(root->children[edgeID] != NULL){
                root->children[edgeID]->suffixLink = root;
                root->reverseSuffixLinks.push_back(root->children[edgeID]);
                q.push(root->children[edgeID]);
            }
        }

        while(!q.empty()){
            Trie* node = q.front();
            q.pop();

            for(int edgeID = 0; edgeID < ALPHABET_SIZE; ++edgeID){
                if(node->children[edgeID] != NULL){
                    Trie* tempNode = node->suffixLink;
                    while(tempNode != NULL && tempNode->children[edgeID] == NULL){
                        tempNode = tempNode->suffixLink;
                    }
                    if(tempNode == NULL){
                        node->children[edgeID]->suffixLink = root;
                        root->reverseSuffixLinks.push_back(node->children[edgeID]);
                    }else{
                        node->children[edgeID]->suffixLink = tempNode->children[edgeID];
                        tempNode->children[edgeID]->reverseSuffixLinks.push_back(node->children[edgeID]);
                    }
                    q.push(node->children[edgeID]);
                }
            }
        }
    }

    void matchAllWords(const string& TEXT){
        Trie* root = this;
        Trie* node = root;
        for(char c: TEXT){
            int edgeID = c - FIRST_ELEM;
            while(node != NULL && node->children[edgeID] == NULL){
                node = node->suffixLink;
            }
            if(node == NULL){
                node = root;
            }else{
                node = node->children[edgeID];
            }
            node->matchCount += 1;
        }
    }

    void collectMatchCounts(vector<int>& counts){
        fill(counts.begin(), counts.end(), 0);
        collectMatchCounts(this, counts);
    }
};

int main(){
    ifstream cin("ahocorasick.in");
    ofstream cout("ahocorasick.out");

    string s;
    cin >> s;

    int n;
    cin >> n;

    Trie trie;
    string word;
    for(int i = 0; i < n; ++i){
        cin >> word;
        trie.insert(word, i);
    }
    
    trie.createSuffixLinks();
    trie.matchAllWords(s);

    vector<int> counts(n);
    trie.collectMatchCounts(counts);

    for(int i = 0; i < n; ++i){
        cout << counts[i] << "\n";
    }

    cin.close();
    cout.close();
    return 0;
}