Create 0380-insert-delete-getrandom.go

go/0380-insert-delete-getrandom.go

@@ -0,0 +1,43 @@
+import "math/rand"
+
+type RandomizedSet struct {
+ hash map[int]int
+ array []int
+ length int
+}
+
+func Constructor() RandomizedSet {
+ return RandomizedSet{
+ hash: make(map[int]int),
+ array: []int{},
+ length: 0,
+ }
+}
+
+func (this *RandomizedSet) Insert(val int) bool {
+ if _, ok := this.hash[val]; ok {
+ return false
+ }
+ this.array = append(this.array, val)
+ this.hash[val] = len(this.array) - 1
+ this.length++
+ return true
+}
+
+func (this *RandomizedSet) Remove(val int) bool {
+ idx, ok := this.hash[val]
+ if !ok {
+ return false
+ }
+ last := this.array[this.length-1]
+ this.array[idx] = last
+ this.hash[last] = idx
+ this.array = this.array[:len(this.array)-1]
+ delete(this.hash, val)
+ this.length--
+ return true
+}
+
+func (this *RandomizedSet) GetRandom() int {
+ return this.array[rand.Intn(this.length)]
+}