Find Highest Altitude | Top Placement Question 🔥 | LeetCode 75 #18

Find the Highest Altitude (LeetCode 1732) explained in Hindi — prefix sum the easy way: track your running altitude and the highest point reached in a single pass. In this video: the problem decoded from zero (why gain[i] is a STEP between points, not an altitude), the biker-with-logbook hiking analogy visualized as a live mountain path, the number-one beginner trap (gain is a DIFFERENCE, not the altitude) demolished with two concrete mini-examples, a full animated dry run on gain = [-5, 1, 5, 0, -7] (altitudes [0, -5, -4, 1, 1, -6], answer 1, traced step by step), line-by-line C++ code with the WHY behind every line (why cur starts at 0 and not at gain[0], why best starts at 0, why a running total beats storing an array), a plain-words correctness proof built on the definition of gain, complexity with reasoning (O(n) time, O(1) space), and 5 edge cases (all negative gains, single element, all zeros, a trip that returns to exactly 0, and the n = 100 performance case). Key insight: altitude(point i+1) = altitude(point i) + gain[i]. So the running total at step i IS the altitude at that point — a prefix sum — and the maximum over all points IS the highest altitude. No array needed: two numbers, one pass. Practice here: https://leetcode.com/problems/find-th... Next up: #19 in the LeetCode 75 series. #LeetCode #LeetCode75 #DSAinHindi #PrefixSum #CodingInterview #PlacementPreparation #Cpp #HindiCoding