Merge pull request neetcode-gh#1937 from kkr2/feat/1584-min-cost-to-connect.go

Create 1584-min-cost-to-connect.go

Author: tahsintunan

go/1584-min-cost-to-connect.go

@@ -0,0 +1,64 @@
+func minCostConnectPoints(points [][]int) int {
+
+	n := len(points)
+	adj := make([][][]int, n)
+	for i := 0; i < n; i++ {
+		x1, y1 := points[i][0], points[i][1]
+		for j := i + 1; j < n; j++ {
+			x2, y2 := points[j][0], points[j][1]
+			dist := abs(x1-x2) + abs(y1-y2)
+			adj[i] = append(adj[i], []int{dist, j})
+			adj[j] = append(adj[j], []int{dist, i})
+		}
+	}
+	// prims
+	res := 0
+	visited := make(map[int]bool)
+
+	h := &IntHeap{[2]int{0, 0}}
+
+	for len(visited) < n {
+		pntObj := heap.Pop(h).([2]int)
+		cost, pnt := pntObj[0], pntObj[1]
+
+		if visited[pnt] {
+			continue
+		}
+		res += cost
+		visited[pnt] = true
+
+		for _, neighbour := range adj[pnt] {
+			nCost, nPoint := neighbour[0], neighbour[1]
+
+			if !visited[nPoint] {
+				heap.Push(h, [2]int{nCost, nPoint})
+			}
+		}
+	}
+	return res
+}
+
+func abs(n int) int {
+	if n > 0 {
+		return n
+	}
+	return -n
+}
+
+type IntHeap [][2]int
+
+func (h IntHeap) Len() int           { return len(h) }
+func (h IntHeap) Less(i, j int) bool { return h[i][0] < h[j][0] }
+func (h IntHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }
+
+func (h *IntHeap) Push(x interface{}) {
+	*h = append(*h, x.([2]int))
+}
+
+func (h *IntHeap) Pop() interface{} {
+	old := *h
+	n := len(old)
+	x := old[n-1]
+	*h = old[:n-1]
+	return x
+}