Data commit

Task/Straddling-checkerboard/Go/straddling-checkerboard.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+    "fmt"
+    "strings"
+)
+
+func main() {
+    key := `
+ 8752390146
+ ET AON RIS
+5BC/FGHJKLM
+0PQD.VWXYZU`
+    p := "you have put on 7.5 pounds since I saw you."
+    fmt.Println(p)
+    c := enc(key, p)
+    fmt.Println(c)
+    fmt.Println(dec(key, c))
+}
+
+func enc(bd, pt string) (ct string) {
+    enc := make(map[byte]string)
+    row := strings.Split(bd, "\n")[1:]
+    r2d := row[2][:1]
+    r3d := row[3][:1]
+    for col := 1; col <= 10; col++ {
+        d := string(row[0][col])
+        enc[row[1][col]] = d
+        enc[row[2][col]] = r2d+d
+        enc[row[3][col]] = r3d+d
+    }
+    num := enc['/']
+    delete(enc, '/')
+    delete(enc, ' ')
+    for i := 0; i < len(pt); i++ {
+        if c := pt[i]; c <= '9' && c >= '0' {
+            ct += num + string(c)
+        } else {
+            if c <= 'z' && c >= 'a' {
+                c -= 'a'-'A'
+            }
+            ct += enc[c]
+        }
+    }
+    return
+}
+
+func dec(bd, ct string) (pt string) {
+    row := strings.Split(bd, "\n")[1:]
+    var cx [10]int
+    for i := 1; i <= 10; i++ {
+        cx[row[0][i]-'0'] = i
+    }
+    r2d := row[2][0]-'0'
+    r3d := row[3][0]-'0'
+    for i := 0; i < len(ct); i++ {
+        var r int
+        switch d := ct[i]-'0'; d {
+        case r2d:
+            r = 2
+        case r3d:
+            r = 3
+        default:
+            pt += string(row[1][cx[d]])
+            continue
+        }
+        i++
+        if b := row[r][cx[ct[i]-'0']]; b == '/' {
+            i++
+            pt += string(ct[i])
+        } else {
+            pt += string(b)
+        }
+    }
+    return
+}