Solve 'Design a Simple Automaton (Finite State Machine)' kata (#8)

* Setup kata

* Solve 'Design a Simple Automaton (Finite State Machine)' kata

Author: borisskert

include/design_a_simple_automaton/automaton.h

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+#ifndef CPP_KATAS_AUTOMATON_H
+#define CPP_KATAS_AUTOMATON_H
+
+#include <vector>
+
+class Automaton {
+public:
+    Automaton();
+
+    bool read_commands(const std::vector<char> &commands);
+};
+
+#endif //CPP_KATAS_AUTOMATON_H

src/design_a_simple_automaton/automaton.cpp

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+#include <vector>
+
+/**
+ * https://www.codewars.com/kata/5268acac0d3f019add000203/train/cpp
+ */
+class Automaton {
+public:
+    Automaton();
+
+    bool read_commands(const std::vector<char> &commands);
+};
+
+Automaton::Automaton() = default;
+
+class State {
+public:
+    virtual State *transition(char command) = 0;
+
+    virtual bool is_final() {
+        return false;
+    }
+};
+
+class Q1 : public State {
+    State *transition(char command) override;
+};
+
+class Q2 : public State {
+    State *transition(char command) override;
+
+    bool is_final() override {
+        return true;
+    }
+};
+
+class Q3 : public State {
+    State *transition(char command) override;
+};
+
+bool Automaton::read_commands(const std::vector<char> &commands) {
+    State *state = new Q1();
+
+    for (const char &command: commands) {
+        state = state->transition(command);
+    }
+
+    return state->is_final();
+}
+
+State *Q1::transition(char command) {
+    if (command == '1') {
+        return new Q2();
+    }
+
+    return this;
+}
+
+State *Q2::transition(char c) {
+    if (c == '0') {
+        return new Q3();
+    }
+
+    return this;
+}
+
+State *Q3::transition(char c) {
+    return new Q2();
+}

test/design_a_simple_automaton/automaton_test.cpp

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+#include <igloo/igloo_alt.h>
+#include "design_a_simple_automaton/automaton.h"
+
+using namespace igloo;
+
+Describe(BasicTests) {
+    It(Test1) {
+        auto automata = Automaton();
+        Assert::That(automata.read_commands({'1'}), Equals(true));
+    }
+
+    It(Test2) {
+        auto automata = Automaton();
+        Assert::That(automata.read_commands({'1', '0', '0', '1'}), Equals(true));
+    }
+};