```
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
/** @param head The linked list's head.
Note that the head is guaranteed to be not null, so it contains at least one node. */
Solution(ListNode* head) {
h=head;
}
/** Returns a random node's value. */
int getRandom() {
int cnt=1;
ListNode*p=h;
int res=0;
while(p)
{
int n=rand()%cnt;
if(n==0)
res=p->val;
p=p->next;
cnt++;
}
return res;
}
private:
ListNode* h;
};
/**
* Your Solution object will be instantiated and called as such:
* Solution obj = new Solution(head);```
* int param_1 = obj.getRandom();
*/
```