PayPal's DSA rounds draw on dynamic programming, stack-based design problems, and string/graph patterns — several candidates report being asked to talk through an approach (e.g. topological sort) without necessarily writing full code for every question. The three problems below are real, recently reported (2025) PayPal questions with full solutions.
Given a triangle array of numbers, find the minimum possible sum of a path from the top row to the bottom row. From each cell, you may move to either of the two adjacent cells directly below it in the next row.
Input: triangle = [[2],[3,4],[6,5,7],[4,1,8,3]]
Output: 11
The path 2 → 3 → 5 → 1 sums to 11, the minimum among all top-to-bottom paths.
Design a stack that supports push, pop, top, and retrieving the minimum element, with every operation running in O(1) time.
Input: push(-2), push(0), push(-3), getMin(), pop(), top(), getMin()
Output: -3, then after pop(): 0, -2
getMin() must stay O(1) even after a pop removes the current minimum.
Given an encoded string using the pattern k[encoded_string] — meaning the encoded_string inside the brackets is repeated k times — return the fully decoded string. The encoding can be nested.
Input: s = "3[a2[c]]"
Output: "accaccacc"
Input: s = "2[abc]3[cd]ef"
Output: "abcabccdcdcdef"
More DSA questions PayPal has asked recently
These topics were reported in verified 2025 PayPal loops. Full problem statements, solutions and explanations for these are part of the Placement-Ready PYQ Kit.
5 more verified DSA questions with full solutions in the full Placement-Ready PYQ Kit
Includes every round they were asked in, from the coding round through the final bar-raiser.