Data commit

Task/Bulls-and-cows-Player/Go/bulls-and-cows-player.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+    "bufio"
+    "fmt"
+    "os"
+    "strconv"
+    "strings"
+)
+
+func main() {
+    fmt.Println(`Cows and bulls/player
+You think of four digit number of unique digits in the range 1 to 9.
+I guess.  You score my guess:
+    A correct digit but not in the correct place is a cow.
+    A correct digit in the correct place is a bull.
+You give my score as two numbers separated with a space.`)
+
+    // generate possible patterns, store in map
+    m := make(map[string]int)
+    var g func([]byte, int)
+    g = func(digits []byte, fixed int) {
+        if fixed == 4 {
+            m[string(digits[:4])] = 0
+            return
+        }
+        for i := fixed; i < len(digits); i++ {
+            digits[fixed], digits[i] = digits[i], digits[fixed]
+            g(digits, fixed+1)
+            digits[fixed], digits[i] = digits[i], digits[fixed]
+        }
+    }
+    g([]byte("123456789"), 0)
+
+    // guess/score/eliminate loop
+    for in := bufio.NewReader(os.Stdin);; {
+        // pick a value, ie, guess
+        var guess string
+        for guess = range m {
+            delete(m, guess)
+            break
+        }
+
+        // get and parse score
+        var c, b uint
+        for ;; fmt.Println("Score guess as two numbers: cows bulls") {
+            fmt.Printf("My guess: %s.  Score? (c b) ", guess)
+            score, err := in.ReadString('\n')
+            if err != nil {
+                fmt.Println("\nSo, bye.")
+                return
+            }
+            s2 := strings.Fields(score)
+            if len(s2) == 2 {
+                c2, err := strconv.ParseUint(s2[0], 10, 0)
+                if err == nil && c2 <= 4 {
+                    b2, err := strconv.ParseUint(s2[1], 10, 0)
+                    if err == nil && c2+b2 <= 4 {
+                        c = uint(c2)
+                        b = uint(b2)
+                        break
+                    }
+                }
+            }
+        }
+
+        // check for win
+        if b == 4 {
+            fmt.Println("I did it. :)")
+            return
+        }
+
+        // eliminate patterns with non-matching scores
+        for pat := range m {
+            var cows, bulls uint
+            for ig, cg := range guess {
+                switch strings.IndexRune(pat, cg) {
+                case -1:
+                default: // I just think cows should go first
+                    cows++
+                case ig:
+                    bulls++
+                }
+            }
+            if cows != c || bulls != b {
+                delete(m, pat)
+            }
+        }
+
+        // check for inconsistency
+        if len(m) == 0 {
+            fmt.Println("Oops, check scoring.")
+            return
+        }
+    }
+}