K Closest Points to Origin
Detailed guide and Python implementation for the 'K Closest Points to Origin' problem.
1. Concept Overview
The 'K Closest Points to Origin' problem is a key challenge in the Heap / Priority Queue section.
This implementation focuses on easy-level logic in Python.
We prioritize technical accuracy and code readability in our provided solutions.
2. Real-World Applications
3. Visual Intuition
Visualizing the logic flow for K Closest Points to Origin.
4. Prerequisites
5. Step-by-Step Thinking
1. Understand the problem
Read the problem statement for K Closest Points to Origin carefully.
2. Formulate brute force
Draft a simple iterative solution.
3. Identify inefficiency
Look for redundant calculations.
4. Optimize search path
Use hashing or sorting to speed up the process.
5. Final Implementation
Clean up the code for production standards.
Problem Statement
Given an array of points where points[i] = [xi, yi] represents a point on the X-Y plane and an integer k, return the k closest points to the origin (0, 0).
The distance between two points on the X-Y plane is the Euclidean distance (i.e., sqrt((x1 - x2)^2 + (y1 - y2)^2)).
You may return the answer in any order. The answer is guaranteed to be unique (except for the order that it is in).
Write a function kClosest(points: List[List[int]], k: int) -> List[List[int]].
- •1 <= k <= len(points) <= 10^4
- •-10^4 <= xi, yi <= 10^4
Examples
points = [[1,3],[-2,2]], k = 1
[[-2,2]]
The distance from (1, 3) to the origin is sqrt(10). The distance from (-2, 2) to the origin is sqrt(8). Since sqrt(8) < sqrt(10), (-2, 2) is closer to the origin.
points = [[3,3],[5,-1],[-2,4]], k = 2
[[3,3],[-2,4]]
The closest two points are (3, 3) and (-2, 4). (Order of elements in the output does not matter).
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
Ready to Solve?
Open the problem in PyRun's browser-based Python editor. Your code runs fully offline — no server required.
Interview Insights & Variations
Complexity Analysis Breakdown
Why Time: Directly evaluates all possibilities.
Why Space: Uses standard local memory.
Why Time: Optimized paths reduce total operations.
Why Space: May trade memory for speed.
Optimized Solution Python Code
Optimized Solution Python Code
import heapq
def k_closest_opt(points, k):
minHeap = []
for x, y in points:
dist = (x**2) + (y**2)
minHeap.append([dist, x, y])
heapq.heapify(minHeap)
res = []
while k > 0:
dist, x, y = heapq.heappop(minHeap)
res.append([x, y])
k -= 1
return resBrute Force Code (Spoiler Guarded)
Brute Force Code (Spoiler Guarded)
def k_closest_brute(points, k):
points.sort(key=lambda p: p[0]**2 + p[1]**2)
return points[:k]Algorithm Pattern Checklist
When dealing with Heap / Priority Queue data patterns.
Core Prerequisites
Revision Key Notes
Common Mistakes & Pitfalls
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