Data commit

Task/Tic-tac-toe/Go/tic-tac-toe.go

@@ -0,0 +1,160 @@
+package main
+
+import (
+    "bufio"
+    "fmt"
+    "math/rand"
+    "os"
+    "strings"
+)
+
+var b []byte
+
+func printBoard() {
+    fmt.Printf("%s\n%s\n%s\n", b[0:3], b[3:6], b[6:9])
+}
+
+var pScore, cScore int
+var pMark, cMark byte = 'X', 'O'
+var in = bufio.NewReader(os.Stdin)
+
+func main() {
+    b = make([]byte, 9)
+    fmt.Println("Play by entering a digit.")
+    for {
+        // start of game
+        for i := range b {
+            b[i] = '1' + byte(i)
+        }
+        computerStart := cMark == 'X'
+        if computerStart {
+            fmt.Println("I go first, playing X's")
+        } else {
+            fmt.Println("You go first, playing X's")
+        }
+    TakeTurns:
+        for {
+            if !computerStart {
+                if !playerTurn() {
+                    return
+                }
+                if gameOver() {
+                    break TakeTurns
+                }
+
+            }
+            computerStart = false
+            computerTurn()
+            if gameOver() {
+                break TakeTurns
+            }
+        }
+        fmt.Println("Score: you", pScore, "me", cScore)
+        fmt.Println("\nLet's play again.")
+    }
+}
+
+func playerTurn() bool {
+    var pm string
+    var err error
+    for i := 0; i < 3; i++ { // retry loop
+        printBoard()
+        fmt.Printf("%c's move? ", pMark)
+        if pm, err = in.ReadString('\n'); err != nil {
+            fmt.Println(err)
+            return false
+        }
+        pm = strings.TrimSpace(pm)
+        if pm >= "1" && pm <= "9" && b[pm[0]-'1'] == pm[0] {
+            x := pm[0] - '1'
+            b[x] = pMark
+            return true
+        }
+    }
+    fmt.Println("You're not playing right.")
+    return false
+}
+
+var choices = make([]int, 9)
+
+func computerTurn() {
+    printBoard()
+    var x int
+    defer func() {
+        fmt.Println("My move:", x+1)
+        b[x] = cMark
+    }()
+    // look for two in a row
+    block := -1
+    for _, l := range lines {
+        var mine, yours int
+        x = -1
+        for _, sq := range l {
+            switch b[sq] {
+            case cMark:
+                mine++
+            case pMark:
+                yours++
+            default:
+                x = sq
+            }
+        }
+        if mine == 2 && x >= 0 {
+            return // strategy 1: make winning move
+        }
+        if yours == 2 && x >= 0 {
+            block = x
+        }
+    }
+    if block >= 0 {
+        x = block // strategy 2: make blocking move
+        return
+    }
+    // default strategy: random move
+    choices = choices[:0]
+    for i, sq := range b {
+        if sq == '1'+byte(i) {
+            choices = append(choices, i)
+        }
+    }
+    x = choices[rand.Intn(len(choices))]
+}
+
+func gameOver() bool {
+    // check for win
+    for _, l := range lines {
+        if b[l[0]] == b[l[1]] && b[l[1]] == b[l[2]] {
+            printBoard()
+            if b[l[0]] == cMark {
+                fmt.Println("I win!")
+                cScore++
+                pMark, cMark = 'X', 'O'
+            } else {
+                fmt.Println("You win!")
+                pScore++
+                pMark, cMark = 'O', 'X'
+            }
+            return true
+        }
+    }
+    // check for empty squares
+    for i, sq := range b {
+        if sq == '1'+byte(i) {
+            return false
+        }
+    }
+    fmt.Println("Cat game.")
+    pMark, cMark = cMark, pMark
+    return true
+}
+
+var lines = [][]int{
+    {0, 1, 2}, // rows
+    {3, 4, 5},
+    {6, 7, 8},
+    {0, 3, 6}, // columns
+    {1, 4, 7},
+    {2, 5, 8},
+    {0, 4, 8}, // diagonals
+    {2, 4, 6},
+}