new files

Task/Search-a-list/Go/search-a-list.go

@@ -0,0 +1,79 @@
+package main
+
+import "fmt"
+
+var haystack = []string{"Zig", "Zag", "Wally", "Ronald", "Bush", "Krusty",
+    "Charlie", "Bush", "Bozo", "Zag", "mouse", "hat", "cup", "deodorant",
+    "television", "soap", "methamphetamine", "severed cat heads", "foo",
+    "bar", "baz", "quux", "quuux", "quuuux", "bazola", "ztesch", "foo",
+    "bar", "thud", "grunt", "foo", "bar", "bletch", "foo", "bar", "fum",
+    "fred", "jim", "sheila", "barney", "flarp", "zxc", "spqr", ";wombat",
+    "shme", "foo", "bar", "baz", "bongo", "spam", "eggs", "snork", "foo",
+    "bar", "zot", "blarg", "wibble", "toto", "titi", "tata", "tutu", "pippo",
+    "pluto", "paperino", "aap", "noot", "mies", "oogle", "foogle", "boogle",
+    "zork", "gork", "bork", "sodium", "phosphorous", "californium",
+    "copernicium", "gold", "thallium", "carbon", "silver", "gold", "copper",
+    "helium", "sulfur"}
+
+func main() {
+    // first task
+    printSearchForward("soap")
+    printSearchForward("gold")
+    printSearchForward("fire")
+    // extra task
+    printSearchReverseMult("soap")
+    printSearchReverseMult("gold")
+    printSearchReverseMult("fire")
+}
+
+// First task solution uses panic as an exception-like mechanism, as requested
+// by the task.  Note however, this is not idiomatic in Go and in fact
+// is considered bad practice.
+func printSearchForward(s string) {
+    fmt.Printf("Forward search: %s: ", s)
+    defer func() {
+        if x := recover(); x != nil {
+            if err, ok := x.(string); ok && err == "no match" {
+                fmt.Println(err)
+                return
+            }
+            panic(x)
+        }
+    }()
+    fmt.Println("smallest index =", searchForwardPanic(s))
+}
+
+func searchForwardPanic(s string) int {
+    for i, h := range haystack {
+        if h == s {
+            return i
+        }
+    }
+    panic("no match")
+    return -1
+}
+
+// Extra task, a quirky search for multiple occurrences.  This is written
+// without panic, and shows more acceptable Go programming practice.
+func printSearchReverseMult(s string) {
+    fmt.Printf("Reverse search for multiples: %s: ", s)
+    if i := searchReverseMult(s); i > -1 {
+        fmt.Println("largest index =", i)
+    } else {
+        fmt.Println("no multiple occurrence")
+    }
+}
+
+func searchReverseMult(s string) int {
+    largest := -1
+    for i := len(haystack) - 1; i >= 0; i-- {
+        switch {
+        case haystack[i] != s:
+        case largest == -1:
+            largest = i
+        default:
+            return largest
+        }
+    }
+    return -1
+}