Enigma C++ Perf

gistfile1.cpp

#include <iostream>
#include <cstring>
#include <array>
using namespace std;

const std::array<char, 27> alpha = {"ABCDEFGHIJKLMNOPQRSTUVWXYZ"};
const std::array<std::array<char, 27>, 3> rotors
{
    {{"EKMFLGDQVZNTOWYHXUSPAIBRCJ"},
    {"AJDKSIRUXBLHWTMCQGZNPYFVOE"},
    {"BDFHJLCPRTXVZNYEIWGAKMUSQO"}}
};

const std::array<char, 27> reflector = {"YRUHQSLDPXNGOKMIEBFZCWVJAT"};
const std::array<char, 4> key = {"ABC"};


long mod26(long a)
{
  return (a+26)%26;
}

int li (char l)
{
  return l - 'A';
}

template <size_t N>
std::size_t index_of (const std::array<char, N>& str, int find)
{
    for(std::size_t i = 0; i < N; ++i) {
        if(str[i] == find) return i;
    }
    return -1;
}

template <size_t N>
std::array<char, N> crypt (const std::array<char, N>& ct)
{
  int L = li(key[0]);
  int M = li(key[1]);
  int R = li(key[2]);

  std::array<char, N> output;

  for ( unsigned x = 0; x < N ; ++x ) {
    int ct_letter = li(ct[x]);

    R = mod26(R + 1);

    char a = rotors[2][mod26(R + ct_letter)];
    char b = rotors[1][mod26(M + li(a) - R)];
    char c = rotors[0][mod26(L + li(b) - M)];

    char ref = reflector[mod26(li(c) - L)];

    int d = mod26(index_of(rotors[0], alpha[mod26(li(ref) + L)]) - L);
    int e = mod26(index_of(rotors[1], alpha[mod26(d + M)]) - M);
    char f = alpha[mod26(index_of(rotors[2], alpha[mod26(e + R)]) - R)];
    // std::cout << f;
    output[x] = f;
  }

  return output;
}

int main ()
{
  for ( int i = 0; i < 1000000; i++) {
  	crypt(std::array<char, 37>{"PZUFWDSASJGQGNRMAEODZJXQQKHSYGVUSGSU"});
  }
  
  // crypt(std::array<char, 37>{"PZUFWDSASJGQGNRMAEODZJXQQKHSYGVUSGSU"});

  return 0;
}