Pattern Searching using a Trie of all Suffixes

来源：互联网发布：java fastjson转map 编辑：程序博客网时间：2024/05/17 06:57

以下是构造banana\0的后缀树：

具体代码如下：

#include <iostream>#include <list>#define MAX_CHAR 256using namespace std;class SuffixTrieNode{private:SuffixTrieNode *children[MAX_CHAR];list<int> *indexes;public:SuffixTrieNode(){indexes = new list<int>;for(int i = 0; i < MAX_CHAR; ++i)children[i] = NULL;}void insertSuffix(string suffix, int index);list<int>* search(string pat);};class SuffixTrie{private:SuffixTrieNode root;public:SuffixTrie(string txt){for(int i = 0; i < txt.length(); ++i)root.insertSuffix(txt.substr(i), i);};void search(string pat);};void SuffixTrieNode::insertSuffix(string suffix, int index){indexes->push_front(index);if(suffix.length() > 0){char cIndex = suffix.at(0);if(children[cIndex] == NULL)children[cIndex] = new SuffixTrieNode();children[cIndex]->insertSuffix(suffix.substr(1), index + 1);}}list<int>* SuffixTrieNode::search(string pat){if(pat.length() == 0)return indexes;if(children[pat.at(0)] != NULL)return children[pat.at(0)]->search(pat.substr(1));elsereturn NULL;} void SuffixTrie::search(string pat){list<int>* result = root.search(pat);if(result == NULL)cout<<"Pattern not found!"<<endl;else{int patLen = pat.length();for(list<int>::iterator it = result->begin(); it != result->end(); ++it)cout<<"Pattern found at position "<<*it - patLen<<endl;}}int main() {//freopen("input.txt","r",stdin);    //freopen("output.txt", "w", stdout);    string txt = "geeksforgeeks.org";    SuffixTrie S(txt);     cout << "Search for 'ee'" << endl;    S.search("ee");     cout << "\nSearch for 'geek'" << endl;    S.search("geek");     cout << "\nSearch for 'quiz'" << endl;    S.search("quiz");     cout << "\nSearch for 'forgeeks'" << endl;    S.search("forgeeks");return 0;}

转载于：http://www.geeksforgeeks.org/pattern-searching-using-trie-suffixes/

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