Data commit

Task/Best-shuffle/Julia/best-shuffle.julia

@@ -0,0 +1,52 @@
+# v0.6
+
+function bestshuffle(str::String)::Tuple{String,Int}
+    s = Vector{Char}(str)
+
+    # Count the supply of characters.
+    cnt = Dict{Char,Int}(c => 0 for c in s)
+    for c in s; cnt[c] += 1 end
+
+    # Allocate the result
+    r = similar(s)
+    for (i, x) in enumerate(s)
+        # Find the best character to replace x.
+        best = x
+        rankb = -2
+        for (c, rankc) in cnt
+            # Prefer characters with more supply.
+            # (Save characters with less supply.)
+            # Avoid identical characters.
+            if c == x; rankc = -1 end
+            if rankc > rankb
+                best = c
+                rankb = rankc
+            end
+        end
+
+        # Add character to list. Remove it from supply.
+        r[i] = best
+        cnt[best] -= 1
+        if cnt[best] == 0; delete!(cnt, best) end
+    end
+
+    # If the final letter became stuck (as "ababcd" became "bacabd",
+    # and the final "d" became stuck), then fix it.
+    i = length(s)
+    if r[i] == s[i]
+        for j in 1:i
+            if r[i] != s[j] && r[j] != s[i]
+                r[i], r[j] = r[j], r[i]
+                break
+            end
+        end
+    end
+
+    score = sum(x == y for (x, y) in zip(r, s))
+    return r, score
+end
+
+for word in ("abracadabra", "seesaw", "elk", "grrrrrr", "up", "a")
+    shuffled, score = bestshuffle(word)
+    println("$word: $shuffled ($score)")
+end