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annotate enigma/rotor.cpp @ 0:74ebb2150658

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Initial commit. Working on the rotor class.
author Brian Neal <bgneal@gmail.com>
date Thu, 21 Jun 2012 21:05:26 -0500
parents
children 1459e74fda3f
rev   line source
bgneal@0 1 // Copyright (C) 2012 by Brian Neal.
bgneal@0 2 // This file is part of Cpp-Enigma, the Enigma Machine simulation.
bgneal@0 3 // Cpp-Enigma is released under the MIT License (see License.txt).
bgneal@0 4 //
bgneal@0 5 // rotor.cpp - Implementation file for the rotor class.
bgneal@0 6
bgneal@0 7 #include <set>
bgneal@0 8 #include <array>
bgneal@0 9 #include <algorithm>
bgneal@0 10 #include "rotor.h"
bgneal@0 11
bgneal@0 12 using namespace enigma;
bgneal@0 13
bgneal@0 14 namespace
bgneal@0 15 {
bgneal@0 16 const char* const ucase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
bgneal@0 17 const std::set<char> ucase_set(ucase, ucase + 26);
bgneal@0 18 }
bgneal@0 19
bgneal@0 20 rotor::rotor(const char* name, const char* wiring, int ring_setting, const char* stepping)
bgneal@0 21 : rotor_name(name),
bgneal@0 22 wiring_str(wiring),
bgneal@0 23 ring_setting(ring_setting),
bgneal@0 24 pos(0),
bgneal@0 25 rotations(0)
bgneal@0 26 {
bgneal@0 27 // check wiring length
bgneal@0 28 if (wiring_str.size() != 26)
bgneal@0 29 {
bgneal@0 30 throw rotor_error("invalid wiring length");
bgneal@0 31 }
bgneal@0 32
bgneal@0 33 // ensure wiring contains only uppercase letters & every char must appear
bgneal@0 34 // exactly once:
bgneal@0 35
bgneal@0 36 std::array<int, 26> letter_counts {{ 0 }};
bgneal@0 37 for (int i = 0; i < 26; ++i)
bgneal@0 38 {
bgneal@0 39 const char c(wiring_str[i]);
bgneal@0 40
bgneal@0 41 if (ucase_set.find(c) == ucase_set.end())
bgneal@0 42 {
bgneal@0 43 throw rotor_error("invalid wiring");
bgneal@0 44 }
bgneal@0 45 ++letter_counts[c - 'A'];
bgneal@0 46 }
bgneal@0 47
bgneal@0 48 if (std::find_if(letter_counts.begin(),
bgneal@0 49 letter_counts.end(),
bgneal@0 50 [](int n) { return n != 1; }) != letter_counts.end())
bgneal@0 51 {
bgneal@0 52 throw rotor_error("invalid wiring; duplicate letter");
bgneal@0 53 }
bgneal@0 54 }