PayPal Interview Questions — 100 DSA Problems

94 problems with full solutions in Python, Java, C++, JavaScript, Go, Rust.

Most frequently asked PayPal LeetCode questions for software engineering interviews.

• Zigzag Conversion (MEDIUM) — String
• LRU Cache (MEDIUM) — Hash Table, Linked List, Design, Doubly-Linked List
• Minimum Replacements to Sort the Array (HARD) — Array, Math, Greedy
• Count Vowel Strings in Ranges (MEDIUM) — Array, String, Prefix Sum
• Count the Number of Vowel Strings in Range (EASY) — Array, String, Counting
• Meeting Scheduler (MEDIUM) — Array, Two Pointers, Sorting
• Maximum Number of Integers to Choose From a Range I (MEDIUM) — Array, Hash Table, Binary Search, Greedy, Sorting
• Number of Valid Move Combinations On Chessboard (HARD) — Array, String, Backtracking, Simulation
• Word Search (MEDIUM) — Array, String, Backtracking, Depth-First Search, Matrix
• Time Needed to Rearrange a Binary String (MEDIUM) — String, Dynamic Programming, Simulation
• Number of Islands (MEDIUM) — Array, Depth-First Search, Breadth-First Search, Union Find, Matrix
• Maximum Frequency Score of a Subarray (HARD) — Array, Hash Table, Math, Stack, Sliding Window
• Minimum Non-Zero Product of the Array Elements (MEDIUM) — Math, Greedy, Recursion
• Maximum Number of Integers to Choose From a Range II (MEDIUM) — Array, Binary Search, Greedy, Sorting
• Paint House III (HARD) — Array, Dynamic Programming
• Maximum Sum Obtained of Any Permutation (MEDIUM) — Array, Greedy, Sorting, Prefix Sum
• Count Array Pairs Divisible by K (HARD) — Array, Math, Number Theory
• Smallest Greater Multiple Made of Two Digits (MEDIUM) — Math, Enumeration
• Best Time to Buy and Sell Stock (EASY) — Array, Dynamic Programming
• Group Anagrams (MEDIUM) — Array, Hash Table, String, Sorting
• Longest Increasing Subsequence (MEDIUM) — Array, Binary Search, Dynamic Programming
• Maximal Square (MEDIUM) — Array, Dynamic Programming, Matrix
• Two Sum (EASY) — Array, Hash Table
• Product of Array Except Self (MEDIUM) — Array, Prefix Sum
• Coin Change (MEDIUM) — Array, Dynamic Programming, Breadth-First Search
• Pairs of Songs With Total Durations Divisible by 60 (MEDIUM) — Array, Hash Table, Counting
• Longest Substring Without Repeating Characters (MEDIUM) — Hash Table, String, Sliding Window
• Minimum Absolute Difference (EASY) — Array, Sorting
• Merge Intervals (MEDIUM) — Array, Sorting
• Merge Sorted Array (EASY) — Array, Two Pointers, Sorting
• Subarray Sum Equals K (MEDIUM) — Array, Hash Table, Prefix Sum
• Find the Smallest Divisor Given a Threshold (MEDIUM) — Array, Binary Search
• Maximum Number of Events That Can Be Attended (MEDIUM) — Array, Greedy, Sorting, Heap (Priority Queue)
• Loud and Rich (MEDIUM) — Array, Depth-First Search, Graph, Topological Sort
• Reorganize String (MEDIUM) — Hash Table, String, Greedy, Sorting, Heap (Priority Queue), Counting
• Valid Anagram (EASY) — Hash Table, String, Sorting
• Count Vowel Substrings of a String (EASY) — Hash Table, String
• Valid Parentheses (EASY) — String, Stack
• Trapping Rain Water (HARD) — Array, Two Pointers, Dynamic Programming, Stack, Monotonic Stack
• House Robber (MEDIUM) — Array, Dynamic Programming
• Meeting Rooms III (HARD) — Array, Hash Table, Sorting, Heap (Priority Queue), Simulation
• Random Pick with Weight (MEDIUM) — Array, Math, Binary Search, Prefix Sum, Randomized
• Sort Colors (MEDIUM) — Array, Two Pointers, Sorting
• Last Stone Weight (EASY) — Array, Heap (Priority Queue)
• Top K Frequent Elements (MEDIUM) — Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect
• Minimum Increment to Make Array Unique (MEDIUM) — Array, Greedy, Sorting, Counting
• Maximum Subarray (MEDIUM) — Array, Divide and Conquer, Dynamic Programming
• Median of Two Sorted Arrays (HARD) — Array, Binary Search, Divide and Conquer
• Kth Largest Element in an Array (MEDIUM) — Array, Divide and Conquer, Sorting, Heap (Priority Queue), Quickselect
• Rotate Image (MEDIUM) — Array, Math, Matrix