#13 Medium Time O(n) Space O(1) Animated

Container With Most Water

Find two lines that together with the x-axis forms a container with maximum water.

LeetCode ↗

Tutor Mode Build the mental model before you memorize the code.

1 Predict
2 Trace
3 Explain
4 Implement

Pattern Two pointers shrink the search space

Use ordering or symmetry to decide which boundary can move without discarding a valid answer.

Approach: Two Pointers (Greedy)

Click play to start

Step 0 / 0

Press play to start the visualization.

1×

Core Insight

Use ordering or symmetry to decide which boundary can move without discarding a valid answer.

Common Pitfall

Move the pointer justified by the comparison; moving both can skip a valid pair.

Description

Find two lines that together with the x-axis forms a container with maximum water.

Constraints

Time Complexity: O(n)
Space Complexity: O(1)

Solution — Two Pointers (Greedy)

TimeO(n) SpaceO(1)

Implementation Plan

Translate the invariant into these small, testable moves.

Place pointers at the relevant boundaries.
Evaluate the pair or window.
Use the comparison to move exactly one boundary.
Stop when the pointers cross or the target is found.

def maxArea(height):
    res = 0
    l, r = 0, len(height) - 1

    while l < r:
        area = (r - l) * min(height[l], height[r])
        res = max(res, area)
        
        if height[l] < height[r]:
            l += 1
        else:
            r -= 1
            
    return res

3Sum

Trapping Rain Water

Container With Most Water

Steps

Description

Constraints

Tags

Solution — Two Pointers (Greedy)