Merge pull request neetcode-gh#1937 from kkr2/feat/1584-min-cost-to-c…

…onnect.go

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

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
+}