Convert 10 of the problems into timed coding tests

Timed Coding Test 1

Problem: First Non-Repeating Character in a String
Description: Find the first character that does not repeat in a string.
Time Limit: 20 minutes

Timed Coding Test 2

Problem: Merge Two Sorted Linked Lists
Description: Merge two sorted singly linked lists and return the sorted merged list.
Time Limit: 25 minutes

Timed Coding Test 3

Problem: Binary Search in a Sorted Array
Description: Implement a binary search algorithm to find the target element’s index in a sorted array.
Time Limit: 15 minutes

Timed Coding Test 4

Problem: Longest Substring Without Repeating Characters
Description: Find the length of the longest substring without duplicate characters.
Time Limit: 25 minutes

Timed Coding Test 5

Problem: Detect Cycle in a Linked List
Description: Determine if a linked list has a cycle using Floyd’s cycle detection algorithm.
Time Limit: 20 minutes

Timed Coding Test 6

Problem: Group Anagrams
Description: Given a list of strings, group anagrams together.
Time Limit: 25 minutes

Timed Coding Test 7

Problem: Rotate Array by k Steps
Description: Rotate an array to the right by k steps in-place.
Time Limit: 20 minutes

Timed Coding Test 8

Problem: Word Break Using Dynamic Programming
Description: Determine if a string can be segmented into space-separated dictionary words.
Time Limit: 30 minutes

Timed Coding Test 9

Problem: Implement LRU Cache
Description: Design a Least Recently Used (LRU) cache with O(1) time for get and put methods.
Time Limit: 40 minutes

Timed Coding Test 10

Problem: Number of Islands in a Grid
Description: Count the number of islands (connected groups of '1's) in a 2D grid.
Time Limit: 30 minutes

These timed tests help train problem-solving speed, code correctness, and time management under typical coding interview constraints. Use a timer and avoid external help to simulate real coding rounds.