#2358

Maximum Number of Groups Entering a Competition

Medium
ArrayMathBinary SearchGreedyGreedySorting
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Approaches

Brute ForceOptimal
Complexity Comparison
Brute ForceOptimal Solution
Time
O(n²)
O(n log n)
Space
O(1)
O(1)
💡

Intuition

Time O(n log n)Space O(1)

The optimal solution leverages the sorted order of grades to systematically form groups of increasing size and sum. By sorting the grades first, we can easily ensure that the conditions for group formation are met.

⚙️

Algorithm

3 steps
  1. 1Step 1: Sort the grades array in ascending order.
  2. 2Step 2: Initialize variables for group size and total groups formed.
  3. 3Step 3: Iterate through the sorted grades, forming groups of increasing size until the conditions can no longer be met.
solution.py16 lines
1# Full working Python code
2
3def maxGroups(grades):
4    grades.sort()
5    total_groups = 0
6    current_size = 1
7    current_sum = 0
8
9    for grade in grades:
10        current_sum += grade
11        if current_size <= total_groups + 1:
12            total_groups += 1
13            current_size += 1
14            current_sum = 0  # Reset sum for the next group
15
16    return total_groups

Complexity note: The sorting step takes O(n log n), and the subsequent iteration through the grades is O(n), making this approach efficient overall.

  • 1Sorting the grades helps in easily forming valid groups.
  • 2The conditions for group formation create a natural sequence of increasing group sizes.

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