Data commit

Task/15-puzzle-solver/Go/15-puzzle-solver.go

@@ -0,0 +1,242 @@
+package main
+
+import "fmt"
+
+var (
+    Nr = [16]int{3, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3}
+    Nc = [16]int{3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2}
+)
+
+var (
+    n, _n      int
+    N0, N3, N4 [85]int
+    N2         [85]uint64
+)
+
+const (
+    i = 1
+    g = 8
+    e = 2
+    l = 4
+)
+
+func fY() bool {
+    if N2[n] == 0x123456789abcdef0 {
+        return true
+    }
+    if N4[n] <= _n {
+        return fN()
+    }
+    return false
+}
+
+func fZ(w int) bool {
+    if w&i > 0 {
+        fI()
+        if fY() {
+            return true
+        }
+        n--
+    }
+    if w&g > 0 {
+        fG()
+        if fY() {
+            return true
+        }
+        n--
+    }
+    if w&e > 0 {
+        fE()
+        if fY() {
+            return true
+        }
+        n--
+    }
+    if w&l > 0 {
+        fL()
+        if fY() {
+            return true
+        }
+        n--
+    }
+    return false
+}
+
+func fN() bool {
+    switch N0[n] {
+    case 0:
+        switch N3[n] {
+        case 'l':
+            return fZ(i)
+        case 'u':
+            return fZ(e)
+        default:
+            return fZ(i + e)
+        }
+    case 3:
+        switch N3[n] {
+        case 'r':
+            return fZ(i)
+        case 'u':
+            return fZ(l)
+        default:
+            return fZ(i + l)
+        }
+    case 1, 2:
+        switch N3[n] {
+        case 'l':
+            return fZ(i + l)
+        case 'r':
+            return fZ(i + e)
+        case 'u':
+            return fZ(e + l)
+        default:
+            return fZ(l + e + i)
+        }
+    case 12:
+        switch N3[n] {
+        case 'l':
+            return fZ(g)
+        case 'd':
+            return fZ(e)
+        default:
+            return fZ(e + g)
+        }
+    case 15:
+        switch N3[n] {
+        case 'r':
+            return fZ(g)
+        case 'd':
+            return fZ(l)
+        default:
+            return fZ(g + l)
+        }
+    case 13, 14:
+        switch N3[n] {
+        case 'l':
+            return fZ(g + l)
+        case 'r':
+            return fZ(e + g)
+        case 'd':
+            return fZ(e + l)
+        default:
+            return fZ(g + e + l)
+        }
+    case 4, 8:
+        switch N3[n] {
+        case 'l':
+            return fZ(i + g)
+        case 'u':
+            return fZ(g + e)
+        case 'd':
+            return fZ(i + e)
+        default:
+            return fZ(i + g + e)
+        }
+    case 7, 11:
+        switch N3[n] {
+        case 'd':
+            return fZ(i + l)
+        case 'u':
+            return fZ(g + l)
+        case 'r':
+            return fZ(i + g)
+        default:
+            return fZ(i + g + l)
+        }
+    default:
+        switch N3[n] {
+        case 'd':
+            return fZ(i + e + l)
+        case 'l':
+            return fZ(i + g + l)
+        case 'r':
+            return fZ(i + g + e)
+        case 'u':
+            return fZ(g + e + l)
+        default:
+            return fZ(i + g + e + l)
+        }
+    }
+}
+
+func fI() {
+    g := (11 - N0[n]) * 4
+    a := N2[n] & uint64(15<<uint(g))
+    N0[n+1] = N0[n] + 4
+    N2[n+1] = N2[n] - a + (a << 16)
+    N3[n+1] = 'd'
+    N4[n+1] = N4[n]
+    cond := Nr[a>>uint(g)] <= N0[n]/4
+    if !cond {
+        N4[n+1]++
+    }
+    n++
+}
+
+func fG() {
+    g := (19 - N0[n]) * 4
+    a := N2[n] & uint64(15<<uint(g))
+    N0[n+1] = N0[n] - 4
+    N2[n+1] = N2[n] - a + (a >> 16)
+    N3[n+1] = 'u'
+    N4[n+1] = N4[n]
+    cond := Nr[a>>uint(g)] >= N0[n]/4
+    if !cond {
+        N4[n+1]++
+    }
+    n++
+}
+
+func fE() {
+    g := (14 - N0[n]) * 4
+    a := N2[n] & uint64(15<<uint(g))
+    N0[n+1] = N0[n] + 1
+    N2[n+1] = N2[n] - a + (a << 4)
+    N3[n+1] = 'r'
+    N4[n+1] = N4[n]
+    cond := Nc[a>>uint(g)] <= N0[n]%4
+    if !cond {
+        N4[n+1]++
+    }
+    n++
+}
+
+func fL() {
+    g := (16 - N0[n]) * 4
+    a := N2[n] & uint64(15<<uint(g))
+    N0[n+1] = N0[n] - 1
+    N2[n+1] = N2[n] - a + (a >> 4)
+    N3[n+1] = 'l'
+    N4[n+1] = N4[n]
+    cond := Nc[a>>uint(g)] >= N0[n]%4
+    if !cond {
+        N4[n+1]++
+    }
+    n++
+}
+
+func fifteenSolver(n int, g uint64) {
+    N0[0] = n
+    N2[0] = g
+    N4[0] = 0
+}
+
+func solve() {
+    if fN() {
+        fmt.Print("Solution found in ", n, " moves: ")
+        for g := 1; g <= n; g++ {
+            fmt.Printf("%c", N3[g])
+        }
+        fmt.Println()
+    } else {
+        n = 0
+        _n++
+        solve()
+    }
+}
+
+func main() {
+    fifteenSolver(8, 0xfe169b4c0a73d852)
+    solve()
+}