Data commit

Task/Best-shuffle/Nim/best-shuffle.nim

@@ -0,0 +1,34 @@
+import times
+import sequtils
+import strutils
+import random
+
+proc count(s1, s2: string): int =
+    for i, c in s1:
+        if c == s2[i]:
+            result.inc
+
+proc shuffle(str: string): string =
+    var r = initRand(getTime().toUnix())
+    var chrs = toSeq(str.items)
+    for i in 0 ..< chrs.len:
+        let chosen = r.rand(chrs.len-1)
+        swap(chrs[i], chrs[chosen])
+    return chrs.join("")
+
+proc bestShuffle(str: string): string =
+    var chrs = toSeq(shuffle(str).items)
+    for i in chrs.low .. chrs.high:
+        if chrs[i] != str[i]:
+            continue
+        for j in chrs.low .. chrs.high:
+            if chrs[i] != chrs[j] and chrs[i] != str[j] and chrs[j] != str[i]:
+                swap(chrs[i], chrs[j])
+                break
+    return chrs.join("")
+
+when isMainModule:
+    let words = @["abracadabra", "seesaw", "grrrrrr", "pop", "up", "a", "antidisestablishmentarianism"];
+    for w in words:
+        let shuffled = bestShuffle(w)
+        echo "$1 $2 $3" % [w, shuffled, $count(w, shuffled)]