go: add «502. IPO»

Signed-off-by: Matej Focko <me@mfocko.xyz>

go/ipo.go

@@ -0,0 +1,53 @@
+package ipo
+
+import (
+	"cmp"
+	"slices"
+
+	pq "github.com/emirpasic/gods/v2/queues/priorityqueue"
+)
+
+type Project struct {
+	capital int
+	profit  int
+}
+
+func byCapital(a, b Project) int {
+	return cmp.Compare(a.capital, b.capital)
+}
+
+func revCmp[T cmp.Ordered](x, y T) int {
+	return -cmp.Compare(x, y)
+}
+
+func findMaximizedCapital(k int, w int, profits []int, capital []int) int {
+	// construct the list of projects
+	projects := make([]Project, len(profits))
+	for i, _ := range profits {
+		projects[i] = Project{capital: capital[i], profit: profits[i]}
+	}
+	slices.SortFunc(projects, byCapital)
+
+	queue := pq.NewWith[int](revCmp)
+
+	i := 0
+	for range k {
+		// add the affordable projects to the queue
+		for i < len(projects) && projects[i].capital <= w {
+			queue.Enqueue(projects[i].profit)
+			i++
+		}
+
+		// invest into the currently most profitable project
+		profit, ok := queue.Dequeue()
+		if !ok {
+			// ran out of the available projects
+			break
+		}
+
+		// collect the profit
+		w += profit
+	}
+
+	return w
+}