編程算法 - 後綴樹(Suffix Tree) 代碼(C)

後綴樹(Suffix Tree) 代碼(C)

給你一個長字符串s與很多短字符串集合{T1,, T2, ...}, 設計一個方法在s中查詢T1, T2, ..., 要求找出Ti在s中的位置.

代碼:

/*
* main.cpp
*
* Created on: 2014.7.20
* Author: Spike
*/

/*eclipse cdt, gcc 4.8.1*/

#include <iostream>
#include <vector>
#include <map>

using namespace std;

class SuffixTreeNode {
map<char, SuffixTreeNode*> children;
char value;
vector<int> indexes;
public:
SuffixTreeNode() {}
void insertString(string s, int index) {
indexes.push_back(index);
if (s.length() > 0) {
value = s[0];
SuffixTreeNode* child = NULL;
if (children.find(value) != children.end()) {
child = children[value];
} else {
child = new SuffixTreeNode();
children[value] = child;
}
string remainder = s.substr(1);
child->insertString(remainder, index);
}
}

vector<int> getIndexes(string s) {
if (s.length() == 0)
return indexes;
else {
char first = s[0];
if (children.find(first) != children.end()) {
string remainder = s.substr(1);
return children[first]->getIndexes(remainder);
} else {
vector<int> empty;
return empty;
}
}
}

~SuffixTreeNode() {
map<char, SuffixTreeNode*>::iterator it;
for (it!=children.begin(); it!=children.end(); ++it)
delete it->second;
}
};

class SuffixTree {
SuffixTreeNode* root;
public:
SuffixTree(string s) {
root = new SuffixTreeNode;
for (int i=0; i<s.length(); ++i) {
string suffix = s.substr(i);
root->insertString(suffix,i);
}
}
vector<int> getIndexes(string s) {
return root->getIndexes(s);
}

~SuffixTree() {}
};

int main(void)
{
string testString = "mississippi";
string stringList[] = {"is", "sip", "hi", "sis"};
SuffixTree tree (testString);
for (int i=0; i<4; i++) {
vector<int> li = tree.getIndexes(stringList[i]);
if (li.size() != 0) {
cout << stringList[i] << " ";
for (int j=0; j<li.size(); ++j)
cout << li[j] << " ";
cout << endl;
}
}

return 0;
}

輸出:

is 1 4
sip 6
sis 3