June 2018 Update

2018-06-22 20:57:24 +00:00 · 2018-06-22 20:57:24 +00:00 · 22f33d4004
commit 22f33d4004
parent ba8067c3b7
5278 changed files with 84726 additions and 14379 deletions
--- a/Task/Universal-Turing-machine/Kotlin/universal-turing-machine.kotlin
+++ b/Task/Universal-Turing-machine/Kotlin/universal-turing-machine.kotlin
@ -0,0 +1,172 @@
+// version 1.2.10
+
+enum class Dir { LEFT, RIGHT, STAY }
+
+class Rule(
+    val state1: String,
+    val symbol1: Char,
+    val symbol2: Char,
+    val dir: Dir,
+    val state2: String
+)
+
+class Tape(
+    var symbol: Char,
+    var left: Tape? = null,
+    var right: Tape? = null
+)
+
+class Turing(
+    val states: List<String>,
+    val finalStates: List<String>,
+    val symbols: CharArray,
+    val blank: Char,
+    var state: String,
+    tapeInput: CharArray,
+    rules: List<Rule>
+) {
+    var tape: Tape? = null
+    val transitions = Array(states.size) { arrayOfNulls<Rule>(symbols.size) }
+
+    init {
+        for (i in 0 until tapeInput.size) {
+            move(Dir.RIGHT)
+            tape!!.symbol = tapeInput[i]
+        }
+        if (tapeInput.size == 0) move(Dir.RIGHT)
+        while (tape!!.left != null) tape = tape!!.left
+        for (i in 0 until rules.size) {
+            val rule = rules[i]
+            transitions[stateIndex(rule.state1)][symbolIndex(rule.symbol1)] = rule
+        }
+    }
+
+    private fun stateIndex(state: String): Int {
+        val i = states.indexOf(state)
+        return if (i >= 0) i else 0
+    }
+
+    private fun symbolIndex(symbol: Char): Int {
+        val i = symbols.indexOf(symbol)
+        return if (i >= 0) i else 0
+    }
+
+    private fun move(dir: Dir) {
+        val orig = tape
+        when (dir) {
+            Dir.RIGHT -> {
+                if (orig != null && orig.right != null) {
+                    tape = orig.right
+                }
+                else {
+                    tape = Tape(blank)
+                    if (orig != null) {
+                        tape!!.left = orig
+                        orig.right = tape
+                    }
+                }
+            }
+
+            Dir.LEFT -> {
+                if (orig != null && orig.left != null) {
+                    tape = orig.left
+                }
+                else {
+                    tape = Tape(blank)
+                    if (orig != null) {
+                        tape!!.right = orig
+                        orig.left = tape
+                    }
+                }
+            }
+
+            Dir.STAY -> {}
+        }
+    }
+
+    fun printState() {
+        print("%-10s ".format(state))
+        var t = tape
+        while (t!!.left != null ) t = t.left
+        while (t != null) {
+            if (t == tape) print("[${t.symbol}]")
+            else           print(" ${t.symbol} ")
+            t = t.right
+        }
+        println()
+    }
+
+    fun run(maxLines: Int = 20) {
+        var lines = 0
+        while (true) {
+            printState()
+            for (finalState in finalStates) {
+                if (finalState == state) return
+            }
+            if (++lines == maxLines) {
+                println("(Only the first $maxLines lines displayed)")
+                return
+            }
+            val rule = transitions[stateIndex(state)][symbolIndex(tape!!.symbol)]
+            tape!!.symbol = rule!!.symbol2
+            move(rule.dir)
+            state = rule.state2
+        }
+    }
+}
+
+fun main(args: Array<String>) {
+    println("Simple incrementer")
+    Turing(
+        states      = listOf("q0", "qf"),
+        finalStates = listOf("qf"),
+        symbols     = charArrayOf('B', '1'),
+        blank       = 'B',
+        state       = "q0",
+        tapeInput   = charArrayOf('1', '1', '1'),
+        rules       = listOf(
+            Rule("q0", '1', '1', Dir.RIGHT, "q0"),
+            Rule("q0", 'B', '1', Dir.STAY, "qf")
+        )
+    ).run()
+
+    println("\nThree-state busy beaver")
+    Turing(
+        states      = listOf("a", "b", "c", "halt"),
+        finalStates = listOf("halt"),
+        symbols     = charArrayOf('0', '1'),
+        blank       = '0',
+        state       = "a",
+        tapeInput   = charArrayOf(),
+        rules       = listOf(
+            Rule("a", '0', '1', Dir.RIGHT, "b"),
+            Rule("a", '1', '1', Dir.LEFT, "c"),
+            Rule("b", '0', '1', Dir.LEFT, "a"),
+            Rule("b", '1', '1', Dir.RIGHT, "b"),
+            Rule("c", '0', '1', Dir.LEFT, "b"),
+            Rule("c", '1', '1', Dir.STAY, "halt")
+        )
+    ).run()
+
+    println("\nFive-state two-symbol probable busy beaver")
+    Turing(
+        states      = listOf("A", "B", "C", "D", "E", "H"),
+        finalStates = listOf("H"),
+        symbols     = charArrayOf('0', '1'),
+        blank       = '0',
+        state       = "A",
+        tapeInput   = charArrayOf(),
+        rules       = listOf(
+            Rule("A", '0', '1', Dir.RIGHT, "B"),
+            Rule("A", '1', '1', Dir.LEFT, "C"),
+            Rule("B", '0', '1', Dir.RIGHT, "C"),
+            Rule("B", '1', '1', Dir.RIGHT, "B"),
+            Rule("C", '0', '1', Dir.RIGHT, "D"),
+            Rule("C", '1', '0', Dir.LEFT, "E"),
+            Rule("D", '0', '1', Dir.LEFT, "A"),
+            Rule("D", '1', '1', Dir.LEFT, "D"),
+            Rule("E", '0', '1', Dir.STAY, "H"),
+            Rule("E", '1', '0', Dir.LEFT, "A")
+        )
+    ).run()
+}