# Duplicate Encoder [6 kyu]

[Duplicate Encoder](https://www.codewars.com/kata/54b42f9314d9229fd6000d9c)
6 kyu

## Solution

/**
*** Author: R-CO
*** E-Mail: [e-mail]
*** Date: 2020-07-21
**/
#include <cctype>
#include <cstdlib>
#include <iostream>
using std::cout;
#include <unordered_map>
using std::unordered_map;
#include <string>
using std::string;

struct TestCaseStruct {
  string input;
  string expected_output;
};

using RefMap = unordered_map<char, size_t>;

class DuplicateEncoder {
 public:
  string duplicate_encoder(const string &word) {
    const auto input_size = word.size();
    string output(input_size, '(');
    RefMap ref_map;

    for (size_t index = 0; index < input_size; ++index) {
      const auto ch = static_cast<char>(tolower(word[index]));
      const auto it = ref_map.find(ch);
      if (it != ref_map.end()) {
        output[index] = ')';
        output[it->second] = ')';
        it->second = index;
        continue;
      }

      ref_map[ch] = index;
    }

    return output;
  }
};

int main(int argc, char *argv[]) {
  /*
  "din" = > "((("
  "recede" = > "()()()"
  "Success" = > ")())())"
  "(( @" = > "))(("
        */
  TestCaseStruct test_cases[] = {{"din", "((("},
                                 {"recede", "()()()"},
                                 {"Success", ")())())"},
                                 {"(( @", "))(("}};

  DuplicateEncoder solution;
  for (const auto test_case : test_cases) {
    if (solution.duplicate_encoder(test_case.input) ==
        test_case.expected_output) {
      cout << "test case \"" << test_case.input << "\" is pass." << std::endl;
    } else {
      cout << "test case \"" << test_case.input << "\" is fail." << std::endl;
    }
  }

  return EXIT_SUCCESS;
}

## Result

PASS

###### tags: `CodeWars` `C++`