DSA · Arrays & Two Pointers · #56

Container With Most Water

Module 40 · difficulty 3/5·⏱ 30:00starts on first keystroke

You are given an integer array `height` of length `n`. Each element `height[i]` represents a vertical line drawn at x-coordinate `i` with that height. Two lines, together with the x-axis, form a container that holds water. Implement `maxArea(height)` that returns the **maximum amount of water** a container can store. The area between lines `i` and `j` (with `i < j`) is `min(height[i], height[j]) * (j - i)`. You may not slant the container.

Examples

height = [1,8,6,2,5,4,8,3,7] → 49 — Lines at indices 1 and 8 (heights 8 and 7) give min(8,7) * (8-1) = 7 * 7 = 49.
height = [1,1] → 1 — Only one container possible: min(1,1) * 1 = 1.
height = [4,3,2,1,4] → 16 — Indices 0 and 4 (both height 4): min(4,4) * 4 = 16.

Constraints

· n == height.length
· 2 <= n <= 10^5
· 0 <= height[i] <= 10^4

Session phases

A · Clarify

B · Approach

C · Complexity

D · Edges

E · Code

F · Tradeoff

G · Score

Phase A — Clarify

Ask questions about input bounds, types, and edge constraints.

Ask the coach clarifying questions about the problem.

When you've covered this phase, advance to the next.