LeetCode Daily #3483 - 11 Sep 2026: Unique 3-Digit Even Numbers Explained

LeetCode Daily Challenge, 11 September 2026 — Problem 3483: Unique 3-Digit Even Numbers. Given an array of digits, count how many distinct three-digit even numbers can be formed using them. Each digit can be used at most as many times as it appears, the number can't start with 0, and the last digit has to be even. In this video: Reading the three constraints: no leading zero, even last digit, distinct results Brute force: three nested loops over indices, dedupe with a set Why index-based loops need the "already used" check The counting approach: frequency of each digit, then count valid combinations Why the digit range 0–9 keeps this effectively constant time Dry run with digits = [1,2,3,4] → 12 Complexity of both approaches LeetCode 3483 — Unique 3-Digit Even Numbers: https://leetcode.com/problems/unique-... This is the first video in the Daily Challenge series — one LeetCode problem of the day, solved from brute force to optimal. My full numbered series (problems #1 onward) continues separately. Subscribe to Brute To Best for the daily problem, every day. #leetcode #leetcodedaily #potd #dailychallenge #dsa #arrays #counting #bruteforce #coding #codinginterview #problemsolving #datastructuresandalgorithms #leetcodesolutions #interviewpreparation #brutetobest