Linked List Operations: Swapping Nodes, Removing Nth Node, Finding Intersections, and Detecting Cycles
Pairwise Node Swapping
To swap adjacent nodes in pairs, we utilize a dummy node to simplify edge cases. The core idea involves manipulating pointers to reverse each pair while maintaining proper linkage with the rest of the list. A cursor pointer tracks the predecessor of each pair being processed.
The termination condition varies based on whet ...
Posted on Sat, 20 Jun 2026 16:35:52 +0000 by matt6805
Hash-Based Algorithms for String and Array Problems
1. Valid Anagram
Given two strings s and t, determine if they are anagrams — i.e., contain the exact same characters with the same frequencies.
Since characters are constrained to lowercase English letters, a fixed-size integer array of length 26 suffices for counting frequencies.
public boolean checkAnagram(String text1, String text2) {
i ...
Posted on Fri, 12 Jun 2026 16:26:39 +0000 by FillePille
Linked List Algorithms: Pair Swapping, Node Removal, Intersection Detection, and Cycle Identification
24. Swap Nodes in Pairs
Problem Link: LeetCode 24
Solution:
This problem involves swapping adjacent nodes in a linked list in pairs. A dummy head node simplifies edge case handling, such as when the list has only one or two nodes.
struct ListNode {
int val;
ListNode *next;
ListNode(int x) : val(x), next(nullptr) {}
};
class Soluti ...
Posted on Tue, 19 May 2026 01:54:15 +0000 by Buttero