Given a singly linked list, return a random node's value from the linked list. Each node must have the**same probability** of being chosen.

-`Solution(ListNode head)` Initializes the object with the head of the singly-linked list`head`.

-`int getRandom()` Chooses a node randomly from the list and returns its value. All the nodes of the list should be equally likely to be chosen.

**Example 1:**

Linked List Random Node

package Solution

funcSolution(xbool)bool {

import (

)

typeListNodestruct {

}

typeSolution382struct {

}

funcConstructor(head*ListNode)Solution382 {

s:=Solution382{length:0,head:head}

forwalker:=head;walker!=nil;walker=walker.Next {

s.length++

}

}

func (this*Solution382)GetRandom()int {

ifthis.head==nil {

}

seed:=rand.NewSource(time.Now().UnixNano())

rr:=rand.New(seed)

index:=rr.Intn(this.length)

walker:=this.head

for ;walker!=nil&&index>0;walker=walker.Next {

}

returnwalker.Val

}

funcSolution(countint,head*ListNode) []int {

s:=Constructor(head)

ans:=make([]int,count)

fori:=0;i<count;i++ {

ans[i]=s.GetRandom()

}

sort.Ints(ans)

}

package Solution

import (

)

cases:= []struct {

expect []int

}{

{"TestCase",true,true},

{"TestCase",true,true},

{"TestCase",false,false},

{"TestCase1",6,&ListNode{Val:1,Next:&ListNode{Val:2,Next:&ListNode{Val:3}}}, []int{1,1,2,2,3,3}},

}

fori,c:=rangecases {

t.Run(c.name+" "+strconv.Itoa(i),func(t*testing.T) {

got:=Solution(c.inputs)

if!reflect.DeepEqual(got,c.expect) {

t.Fatalf("expected: %v, but got: %v, with inputs: %v",

c.expect,got,c.inputs)

}

Solution(c.count,c.head)

})

}

}

funcBenchmarkSolution(b*testing.B) {

}

funcExampleSolution() {

}