Dictionaries_FrequencyQueries.cpp

// Dictionaries_FrequencyQueries.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include "pch.h"
#include <iostream>
#include <vector>
#include <string>	
#include <map>
#include <unordered_map>
#include <functional>
#include <algorithm>

using namespace std;

string ltrim(const string &);
string rtrim(const string &);
vector<string> split(const string &);

// Complete the freqQuery function below.
vector<int> freqQuery(vector<vector<int>> queries) {
	unordered_map<int, int> map_C;
	unordered_map<int, int> map_Freq;
	vector<int> outputVec;
	for (size_t i = 0; i < queries.size(); i++) {
		switch (queries[i][0]) {
		case 1:
			map_C[map_Freq[queries[i][1]]]--;
			map_Freq[queries[i][1]]++;
			map_C[map_Freq[queries[i][1]]]++;
			break;
		case 2:
			if (map_C[map_Freq[queries[i][1]]] > 0) {
				map_C[map_Freq[queries[i][1]]]--;
			}
			if (map_Freq[queries[i][1]] > 0) {
				map_Freq[queries[i][1]]--;
				map_C[map_Freq[queries[i][1]]]++;
			}
			break;
		case 3:
			if (map_C[queries[i][1]] > 0)
				outputVec.push_back(1);
			else
				outputVec.push_back(0);
			break;
		}
	}

	return outputVec;
}

int main()
{
	string q_temp;
	getline(cin, q_temp);

	int q = stoi(ltrim(rtrim(q_temp)));

	vector<vector<int>> queries(q);

	for (int i = 0; i < q; i++) {
		queries[i].resize(2);

		string queries_row_temp_temp;
		getline(cin, queries_row_temp_temp);

		vector<string> queries_row_temp = split(rtrim(queries_row_temp_temp));

		for (int j = 0; j < 2; j++) {
			int queries_row_item = stoi(queries_row_temp[j]);

			queries[i][j] = queries_row_item;
		}
	}

	vector<int> ans = freqQuery(queries);

	for (int i = 0; i < ans.size(); i++) {
		cout << ans[i];

		if (i != ans.size() - 1) {
			cout << "\n";
		}
	}

	cout << "\n";


	return 0;
}

string ltrim(const string &str) {
	string s(str);

	s.erase(
		s.begin(),
		find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace)))
	);

	return s;
}

string rtrim(const string &str) {
	string s(str);

	s.erase(
		find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(),
		s.end()
	);

	return s;
}

vector<string> split(const string &str) {
	vector<string> tokens;

	string::size_type start = 0;
	string::size_type end = 0;

	while ((end = str.find(" ", start)) != string::npos) {
		tokens.push_back(str.substr(start, end - start));

		start = end + 1;
	}

	tokens.push_back(str.substr(start));

	return tokens;
}