Minimum Area Rectangle II — LeetCode 963 Python Solution

MediumGeometryArrayHash TableMath
Problem
#963
Reading time
4 min

The problem

You are given an array of points in the X-Y plane points where points[i] = [xi, yi]. Return the minimum area of any rectangle formed from these points, with sides not necessarily parallel to the X and Y axes.

Example

Input
points = [[1,2],[2,1],[1,0],[0,1]]
Output
2.00000
Explanation
The minimum area rectangle occurs at [1,2],[2,1],[1,0],[0,1], with an area of 2.

Python solution

Python
class Solution:
    def minAreaFreeRect(self, points: List[List[int]]) -> float:
        s = {(x, y) for x, y in points}
        n = len(points)
        ans = inf
        for i in range(n):
            x1, y1 = points[i]
            for j in range(n):
                if j != i:
                    x2, y2 = points[j]
                    for k in range(j + 1, n):
                        if k != i:
                            x3, y3 = points[k]
                            x4 = x2 - x1 + x3
                            y4 = y2 - y1 + y3
                            if (x4, y4) in s:
                                v21 = (x2 - x1, y2 - y1)
                                v31 = (x3 - x1, y3 - y1)
                                if v21[0] * v31[0] + v21[1] * v31[1] == 0:
                                    w = sqrt(v21[0] ** 2 + v21[1] ** 2)
                                    h = sqrt(v31[0] ** 2 + v31[1] ** 2)
                                    ans = min(ans, w * h)
        return 0 if ans == inf else ans

Complexity

MeasureComplexity
TimeO(n^3)
SpaceO(n), where n is the length of the array \textit{points} auxiliary

Pattern: Math and Number Theory

Find the closed form, the invariant, or the modular identity — and skip the loop entirely. LeetCode 963. Minimum Area Rectangle II is filed here because LeetCode tags it Math and Geometry, which is the vocabulary this hub collects.

The math and number theory guide has the Python template for the pattern and the 485 LeetCode problems that use it.

Related problems

Frequently asked questions

How hard is LeetCode 963. Minimum Area Rectangle II?
LeetCode 963. Minimum Area Rectangle II is rated Medium on LeetCode.
What is the time complexity of LeetCode 963. Minimum Area Rectangle II?
The Python solution on this page runs in O(n^3).
What is the space complexity of LeetCode 963. Minimum Area Rectangle II?
The Python solution on this page uses O(n), where n is the length of the array \textit{points} auxiliary space.
What topics does LeetCode 963. Minimum Area Rectangle II cover?
LeetCode 963. Minimum Area Rectangle II is tagged Geometry, Array, Hash Table and Math on LeetCode.

Stuck on problems like this in a live interview?

Stealth Interview is a desktop app for macOS and Windows. It reads the problem off your screen and returns a working solution with a step-by-step explanation and its time and space complexity — invisible to screen sharing.

Get Stealth Interview