160. Intersection of Two Linked Lists

Problem

Difficulty: Easy
Tags: Hash Table, Linked List, Two Pointers

Intuition

I can definitely say this is the hardest question I’ve solved. I didn’t figure it out how to solve it until I search the problem on google. I had to simplify the problem mathematicaly and combine the two array together. I don’t even understand why it works. need more work for this.

Approach

https://velog.io/@jw9603/LeetCode-160.-Intersection-of-Two-Linked-Lists

Solution

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
struct ListNode *getIntersectionNode(struct ListNode *headA, struct ListNode *headB) {
    struct ListNode* a = headA;
    struct ListNode* b = headB;

    while(a != b){
        if(a){
            a = a->next;
        }
        else{
            a = headB;
        }
        if(b){
            b = b->next;
        }
        else{
            b = headA;
        }
    }
    return a;
}

Complexity

Time: - Space complexity: