Uber SDE 2 Front End L4 Interview Experience Round 1

Round 1 The first round involved a medium-level DSA problem. The interviewer was friendly and made the discussion comfortable.

Problem Statement: You are given an integer n representing the number

Round 1 The first round involved a medium-level DSA problem. The interviewer was friendly and made the discussion comfortable.

Problem Statement: You are given an integer n representing the number of houses in a line, and an array initial_infected indicating the houses infected on day 0. Each day, an infected house spreads the infection to its immediate neighbors (i-1 and i+1, if valid).

Return the number of distinct sequences in which all houses become infected.

Example n = 8 initial_infected = [2, 7]

Output: 48 Explanation: Infection spreads outward from initially infected houses, forming segments of uninfected houses. Each segment can be infected in different valid orders. Edge segments (like [1] and [8]) have only one way. The middle segment [3,4,5,6] can be infected from both sides (2 and 7), so the infection order can interleave in multiple ways. Counting all valid interleavings gives the total number of sequences = 48.