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// 382. Linked List Random Node
#include "leetcode.h"
/*
* given singly linked list, return a random node's value from the linked list.
* each node must have the same probability of being chosen. implement
* 'Solution' class: f1: initialises object with head of signly linked list
* 'head' f2: chooses node randomly from list and returns its value. all nodes
* should be equally likely to be chosen
*/
class Solution {
public:
Solution(ListNode *head) {
this->head = head;
while (head != NULL) {
this->n++;
head = head->next;
}
}
int getRandom() {
int i = rand() % this->n;
ListNode *p = this->head;
while (i) {
p = p->next;
i -= 1;
}
return p->val;
}
private:
int n = 0;
ListNode *head = NULL;
};
int main() {
ListNode *head;
Solution *obj = new Solution(head);
int param_1 = obj->getRandom();
}
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