new files

Task/Caesar-cipher/Go/caesar-cipher-1.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+    "fmt"
+    "strings"
+)
+
+type ckey struct {
+    enc, dec func(rune) rune
+}
+
+func newCaesar(k int) (*ckey, bool) {
+    if k < 1 || k > 25 {
+        return nil, false
+    }
+    rk := rune(k)
+    return &ckey{
+        enc: func(c rune) rune {
+            if c >= 'a' && c <= 'z'-rk || c >= 'A' && c <= 'Z'-rk {
+                return c + rk
+            } else if c > 'z'-rk && c <= 'z' || c > 'Z'-rk && c <= 'Z' {
+                return c + rk - 26
+            }
+            return c
+        },
+        dec: func(c rune) rune {
+            if c >= 'a'+rk && c <= 'z' || c >= 'A'+rk && c <= 'Z' {
+                return c - rk
+            } else if c >= 'a' && c < 'a'+rk || c >= 'A' && c < 'A'+rk {
+                return c - rk + 26
+            }
+            return c
+        },
+    }, true
+}
+
+func (ck ckey) encipher(pt string) string {
+    return strings.Map(ck.enc, pt)
+}
+
+func (ck ckey) decipher(ct string) string {
+    return strings.Map(ck.dec, ct)
+}
+
+func main() {
+    pt := "The five boxing wizards jump quickly"
+    fmt.Println("Plaintext:", pt)
+    for _, key := range []int{0, 1, 7, 25, 26} {
+        ck, ok := newCaesar(key)
+        if !ok {
+            fmt.Println("Key", key, "invalid")
+            continue
+        }
+        ct := ck.encipher(pt)
+        fmt.Println("Key", key)
+        fmt.Println("  Enciphered:", ct)
+        fmt.Println("  Deciphered:", ck.decipher(ct))
+    }
+}

Task/Caesar-cipher/Go/caesar-cipher-2.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+    "fmt"
+    "strings"
+    "unicode"
+)
+
+type ckey struct {
+    enc, dec unicode.SpecialCase
+}
+
+func newCaesar(k int) (*ckey, bool) {
+    if k < 1 || k > 25 {
+        return nil, false
+    }
+    i := uint32(k)
+    r := rune(k)
+    return &ckey{
+        unicode.SpecialCase{
+            {'A', 'Z' - i, [3]rune{r}},
+            {'Z' - i + 1, 'Z', [3]rune{r - 26}},
+            {'a', 'z' - i, [3]rune{r}},
+            {'z' - i + 1, 'z', [3]rune{r - 26}},
+        },
+        unicode.SpecialCase{
+            {'A', 'A' + i - 1, [3]rune{26 - r}},
+            {'A' + i, 'Z', [3]rune{-r}},
+            {'a', 'a' + i - 1, [3]rune{26 - r}},
+            {'a' + i, 'z', [3]rune{-r}},
+        },
+    }, true
+}
+
+func (ck ckey) encipher(pt string) string {
+    return strings.ToUpperSpecial(ck.enc, pt)
+}
+
+func (ck ckey) decipher(ct string) string {
+    return strings.ToUpperSpecial(ck.dec, ct)
+}
+
+func main() {
+    pt := "The five boxing wizards jump quickly"
+    fmt.Println("Plaintext:", pt)
+    for _, key := range []int{0, 1, 7, 25, 26} {
+        ck, ok := newCaesar(key)
+        if !ok {
+            fmt.Println("Key", key, "invalid")
+            continue
+        }
+        ct := ck.encipher(pt)
+        fmt.Println("Key", key)
+        fmt.Println("  Enciphered:", ct)
+        fmt.Println("  Deciphered:", ck.decipher(ct))
+    }
+}