#include <fstream>
#include <string>
#include <tuple>
#include <unordered_map>
#include <memory>
using InstructionWordPair = std::tuple<char, std::string>;
struct TrieNode
{
int OccurrenceCount = 0;
int ChildCount = 0;
std::unordered_map<char, std::shared_ptr<TrieNode>> Children;
};
std::unique_ptr<TrieNode> root(new TrieNode());
InstructionWordPair LineToInstructionAndWord(const std::string& line)
{
char instruction = line[0];
std::string word = line.substr(2);
return std::make_tuple(instruction, word);
}
namespace detail
{
bool Delete(TrieNode& node, const std::string& word, int indexInWord)
{
if (indexInWord == word.length())
{
node.OccurrenceCount--;
}
else
{
const char currentChar = word[indexInWord];
auto child = node.Children[currentChar];
if (Delete(*child, word, indexInWord + 1))
{
node.Children.erase(currentChar);
node.ChildCount--;
}
}
bool nodeIsDeletable = node.OccurrenceCount <= 0 && node.ChildCount <= 0;
return nodeIsDeletable;
}
int CountLongestCommonPrefix(const TrieNode& node, const std::string& word, int indexInWord, int lengthSoFar)
{
if (indexInWord == word.length())
{
return lengthSoFar;
}
const char currentChar = word[indexInWord];
const auto child = node.Children.find(currentChar);
if (child != node.Children.end())
{
return CountLongestCommonPrefix(*child->second, word, indexInWord + 1, lengthSoFar + 1);
}
return lengthSoFar;
}
void AddWordOccurrence(TrieNode& node, const std::string& word, int indexInWord)
{
if (indexInWord == word.length())
{
node.OccurrenceCount++;
}
else
{
char currentChar = word[indexInWord];
auto existingChild = node.Children.find(currentChar);
if (existingChild == node.Children.end())
{
auto newNode = std::make_shared<TrieNode>();
node.Children[currentChar] = newNode;
node.ChildCount++;
AddWordOccurrence(*newNode, word, indexInWord + 1);
}
else
{
AddWordOccurrence(*existingChild->second, word, indexInWord + 1);
}
}
}
int CountOccurrences(const TrieNode& node, const std::string& word, int indexInWord)
{
if (indexInWord == word.length())
{
return node.OccurrenceCount;
}
const char currentChar = word[indexInWord];
const auto child = node.Children.find(currentChar);
if (child != node.Children.end())
{
return CountOccurrences(*child->second, word, indexInWord + 1);
}
return 0;
}
}
void AddWordOccurrence(TrieNode& node, const std::string& word)
{
detail::AddWordOccurrence(node, word, 0);
}
void DeleteWordOccurrence(TrieNode& node, const std::string& word)
{
detail::Delete(node, word, 0);
}
int CountOccurrences(const TrieNode& node, const std::string& word)
{
return detail::CountOccurrences(node, word, 0);
}
int CountLongestCommonPrefix(const TrieNode& node, const std::string& word)
{
return detail::CountLongestCommonPrefix(node, word, 0, 0);
}
void Execute(const InstructionWordPair& instructionAndWord)
{
const char instruction = std::get<0>(instructionAndWord);
const std::string word = std::get<1>(instructionAndWord);
switch (instruction)
{
case('0') :
AddWordOccurrence(*root, word);
break;
case('1') :
DeleteWordOccurrence(*root, word);
break;
case('2') :
printf("%d\n", CountOccurrences(*root, word));
break;
case('3') :
printf("%d\n", CountLongestCommonPrefix(*root, word));
break;
default:
break;
}
}
int main()
{
char line[32];
freopen("trie.in", "r", stdin);
freopen("trie.out", "w", stdout);
fgets(line, 32, stdin);
while (!feof(stdin))
{
char instruction = line[0];
int lineLen = 0;
do
{
lineLen++;
} while (line[lineLen] != '\n');
std::string word(line + 2, line + lineLen);
Execute(std::make_tuple(instruction, word));
fgets(line, 32, stdin);
}
}