The sword refers to the first common node of Offer 52 two linked lists

Github-jz-52 – source :large_blue_diamond: Programmer romance

Problem description

Enter two linked lists to find their first common node.

Method 1:

• Execution time: 68 ms, beating 29.97% of all C++ commits
• Memory consumption: 14.4 MB, beating 100.00% of all C++ commits

Algorithm complexity O(n)

class Solution {
public:
    ListNode* getIntersectionNode(ListNode* headA, ListNode* headB) {
        //* Two traversal Pointers
        ListNode* p = headA;
        ListNode* q = headB;
        while(p ! = q) {if (p==nullptr) {
                p = headB;
            }
            else {
                p = p->next;
            }
            if (q == nullptr) {
                q = headA;
            }
            else{ q = q->next; }}returnp; }};Copy the code