go: add «2182. Construct String With Repeat Limit»

URL:	https://leetcode.com/problems/construct-string-with-repeat-limit/
Signed-off-by: Matej Focko <me@mfocko.xyz>

go/construct-string-with-repeat-limit.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"cmp"
+
+	pq "github.com/emirpasic/gods/v2/queues/priorityqueue"
+)
+
+func repeatLimitedString(s string, repeatLimit int) string {
+	charReversed := func(a, b rune) int {
+		return cmp.Compare(b, a)
+	}
+
+	getFreqs := func() map[rune]int {
+		f := make(map[rune]int)
+		for _, c := range s {
+			count, found := f[c]
+
+			if found {
+				count++
+			} else {
+				count = 1
+			}
+
+			f[c] = count
+		}
+
+		return f
+	}
+	freqs := getFreqs()
+
+	q := pq.NewWith(charReversed)
+	for k, _ := range freqs {
+		q.Enqueue(k)
+	}
+
+	result := []rune{}
+	for c, ok := q.Dequeue(); ok; c, ok = q.Dequeue() {
+		k := min(freqs[c], repeatLimit)
+		for i := 0; i < k; i++ {
+			result = append(result, c)
+		}
+		freqs[c] -= k
+
+		if freqs[c] > 0 {
+			nextC, ok := q.Dequeue()
+			if !ok {
+				break
+			}
+
+			result = append(result, nextC)
+			freqs[nextC]--
+
+			if freqs[nextC] > 0 {
+				q.Enqueue(nextC)
+			}
+			q.Enqueue(c)
+		}
+	}
+
+	return string(result)
+}