CaesarCipher.cpp

#include <bits/stdc++.h>

using namespace std;

string ltrim(const string &);
string rtrim(const string &);

/*
 * Complete the 'caesarCipher' function below.
 *
 * The function is expected to return a STRING.
 * The function accepts following parameters:
 *  1. STRING s
 *  2. INTEGER k
 */

string caesarCipher(string s, int k) {
  for (auto i = 0; i < s.length(); i++) {
    if (s[i] >= 'a' && s[i] <= 'z') {
      s[i] = (s[i] - 'a' + k) % 26 + 'a';
    } else if (s[i] >= 'A' && s[i] <= 'Z') {
      s[i] = (s[i] - 'A' + k) % 26 + 'A';
    } else {
      continue;
    }
  }
  return s;
}

int main() {
  ofstream fout(getenv("OUTPUT_PATH"));

  string n_temp;
  getline(cin, n_temp);

  int n = stoi(ltrim(rtrim(n_temp)));

  string s;
  getline(cin, s);

  string k_temp;
  getline(cin, k_temp);

  int k = stoi(ltrim(rtrim(k_temp)));

  string result = caesarCipher(s, k);

  fout << result << "\n";

  fout.close();

  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;
}