falsesecurity.cpp

#include <bits/stdc++.h>
using namespace std;

int main() {
  map<string, string> to_morse({
    {"A", ".-"},
    {"B", "-..."},
    {"C", "-.-."},
    {"D", "-.."},
    {"E", "."},
    {"F", "..-."},
    {"G", "--."},
    {"H", "...."},
    {"I", ".."},
    {"J", ".---"},
    {"K", "-.-"},
    {"L", ".-.."},
    {"M", "--"},
    {"N", "-."},
    {"O", "---"},
    {"P", ".--."},
    {"Q", "--.-"},
    {"R", ".-."},
    {"S", "..."},
    {"T", "-"},
    {"U", "..-"},
    {"V", "...-"},
    {"W", ".--"},
    {"X", "-..-"},
    {"Y", "-.--"},
    {"Z", "--.."},
    {"_", "..--"},
    {",", ".-.-"},
    {".", "---."},
    {"?", "----"},
  });
  map<string, string> from_morse;
  for (auto [letter, code]: to_morse) {
    from_morse[code] = letter;
  }
  string c;
  while (getline(cin, c)) {
    string mc, m, len;
    for (char l: c) {
      string code = to_morse[string(1, l)];
      mc += code;
      len += to_string(code.size());
    }
    reverse(len.begin(), len.end());
    int nxt = 0;
    for (char n: len) {
      int cnt = n - '0';
      string code;
      while (cnt--) {
        code += mc[nxt];
        nxt++;
      }
      m += from_morse[code];
    }
    cout << m << endl;
  }
  return 0;
}