Entities

#include <algorithm>
#include <array>
#include <iostream>
#include <map>
#include <string>
#include <sstream>
#include <unordered_map>
#include <vector>

std::vector<std::string> readFirstLine();
std::vector<std::string> readLines(std::string& line);
std::unordered_map<std::string, std::vector<std::string>> generateMap(std::vector<std::string>& header);
std::unordered_map<std::string, int> mostFrequent(std::vector<std::string>& column);
void printResult(std::unordered_map<std::string, int>& countFrequent);
int main()
{
    std::string line;
    std::vector<std::string> header{ readFirstLine() };

    std::unordered_map<std::string, std::vector<std::string>> table{ generateMap(header) };


    std::string column;
    std::cin >> column;

    std::unordered_map<std::string, int> countFrequent = mostFrequent(table[column]);
    printResult(countFrequent);
    return 0;
}

void printResult(std::unordered_map<std::string, int>& countFrequent)
{
    int biggest{ INT32_MIN };
    std::pair<std::string, int> result;
    std::unordered_map<std::string, int>::iterator iter;
    for (iter = countFrequent.begin(); iter != countFrequent.end(); ++iter)
    {
        if (iter->second > biggest)
        {
            biggest = iter->second;
            result.first = iter->first;
            result.second = biggest;
        }
    }
    std::cout << result.first << " " << result.second << std::endl;

}

std::unordered_map<std::string, int> mostFrequent(std::vector<std::string>& column)
{
    std::unordered_map<std::string, int> countFrequent;
    for (std::string& element : column)
    {
        if (countFrequent.find(element) != countFrequent.end())
        {
            countFrequent[element] = 1;
        }
        countFrequent[element]++;
    }

    return countFrequent;
}

std::vector<std::string> readLines(std::string& line)
{

    std::string word;
    std::istringstream iStr(line);
    std::vector<std::string> properties;
    while (iStr >> word)
    {
        properties.push_back(word);
    }
    return properties;
}


std::unordered_map<std::string, std::vector<std::string>> generateMap(std::vector<std::string>& header)
{
    size_t headerSize{ header.size() };
    std::vector<std::string> properties;
    std::string line;
    std::getline(std::cin, line);
    std::unordered_map<std::string, std::vector<std::string>> table;
    while (line != "end") {
        properties = readLines(line);
        for (size_t i = 0; i < headerSize; ++i)
        {
            table[header[i]].push_back(properties[i]);
        }
        std::getline(std::cin, line);
    }
    return table;
}

std::vector<std::string> readFirstLine()
{
    std::string word;
    std::string line;
    std::vector<std::string> vec;
    std::getline(std::cin, line);
    std::istringstream iStr(line);
    while (iStr >> word)
    {
        vec.push_back(word);
    }
    return vec;
}