PhonePe SDE-1 OA October 2025 | Wallet Cash-back Collection Optimization & Secured Cross-Platform Escrow Routing

Problem 1 - Wallet Cash-back Collection Optimization Problem Statement PhonePe's merchant rewards engine records a chronological stream of transaction ledger entries represented as an integer array rewards of size N. Each value may be: Positive → Cash-back reward credited. Negative → Processing fee deducted. A product manager wants to highlight a contiguous sequence of transactions that maximizes the total reward value. To satisfy audit requirements, the selected segment must contain at least K transactions. Find the maximum possible reward sum ...