package leetcode import ( "math/rand" "github.com/halfrost/LeetCode-Go/structures" ) // ListNode define type ListNode = structures.ListNode /** * Definition for singly-linked list. * type ListNode struct { * Val int * Next *ListNode * } */ type Solution struct { head *ListNode } /* - @param head The linked list's head. Note that the head is guaranteed to be not null, so it contains at least one node. */ func Constructor(head *ListNode) Solution { return Solution{head: head} } /** Returns a random node's value. */ func (this *Solution) GetRandom() int { scope, selectPoint, curr := 1, 0, this.head for curr != nil { if rand.Float64() < 1.0/float64(scope) { selectPoint = curr.Val } scope += 1 curr = curr.Next } return selectPoint } /** * Your Solution object will be instantiated and called as such: * obj := Constructor(head); * param_1 := obj.GetRandom(); */