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-rw-r--r--other/linked_list_random.cpp40
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diff --git a/other/linked_list_random.cpp b/other/linked_list_random.cpp
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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();
+}