How do you solve Type of Triangle on LeetCode?

Type of Triangle (LeetCode #3024) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(1) time complexity and O(1) space complexity. Key insight: Understanding the triangle inequality theorem is crucial for determining if three sides can form a triangle.

What is the time complexity of Type of Triangle?

The optimal solution for Type of Triangle runs in O(1) time and uses O(1) space. The complexity remains constant as we only evaluate three sides.

What is the brute force solution for Type of Triangle?

The brute force approach for Type of Triangle is Brute Force, with O(1) time complexity and O(1) space complexity. The brute force approach checks all combinations of the three sides to determine if they can form a triangle and then categorizes the triangle type based on the side lengths. The optimal Optimal Solution approach improves this to O(1).

What algorithm or data structure is used to solve Type of Triangle?

Type of Triangle uses the following concepts: Array, Math, Sorting. The recommended patterns to study are: Array, Math.

What are the interview tips for Type of Triangle?

Always explain your thought process clearly while coding. Consider edge cases, such as when all sides are equal or when two sides are equal. Practice explaining the triangle inequality theorem, as it's a common topic.

What are common mistakes when solving Type of Triangle?

Failing to check the triangle inequality before categorizing the triangle type. Confusing the conditions for isosceles and scalene triangles.

#3024

Type of Triangle

Easy

ArrayMathSortingArrayMath

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(1)	O(1)
Space	O(1)	O(1)

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Intuition

Time O(1)Space O(1)

The optimal solution leverages the properties of sets to efficiently determine the number of unique side lengths and checks the triangle inequality in a single pass.

⚙️

Algorithm

3 steps

1Step 1: Check if the sides can form a triangle using the triangle inequality theorem.
2Step 2: Use a set to count the unique side lengths.
3Step 3: Return the triangle type based on the size of the set.

solution.py5 lines

1def triangleType(nums):
2    a, b, c = nums
3    if a + b > c and a + c > b and b + c > a:
4        return 'equilateral' if len(set(nums)) == 1 else 'isosceles' if len(set(nums)) == 2 else 'scalene'
5    return 'none'

ℹ

Complexity note: The complexity remains constant as we only evaluate three sides.

1Understanding the triangle inequality theorem is crucial for determining if three sides can form a triangle.
2Counting unique side lengths helps classify the triangle efficiently.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.