#2928

Distribute Candies Among Children I

Easy
MathCombinatoricsEnumerationCombinatorial CountingDynamic Programming
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Approaches

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

Intuition

Time O(n)Space O(1)

Instead of checking all combinations, we can use a mathematical approach to count valid distributions directly. By calculating the maximum candies each child can receive and using combinatorial counting, we can derive the total number of distributions efficiently.

⚙️

Algorithm

3 steps
  1. 1Step 1: Determine the maximum candies each child can receive, which is the minimum of 'limit' and 'n'.
  2. 2Step 2: Use a combinatorial formula to calculate the number of ways to distribute the remaining candies after ensuring each child gets at least 0 and at most 'limit'.
  3. 3Step 3: Return the total count of valid distributions.
solution.py9 lines
1def distributeCandies(n, limit):
2    max_candies = min(limit, n)
3    count = 0
4    for a in range(max_candies + 1):
5        for b in range(max_candies + 1):
6            c = n - a - b
7            if 0 <= c <= max_candies:
8                count += 1
9    return count

Complexity note: The time complexity is O(n) because we only iterate through possible values of 'a' and 'b', while calculating 'c' directly. The space complexity is O(1) since we only use a few variables for counting.

  • 1Understanding the constraints of the problem helps in optimizing the solution.
  • 2Using combinatorial counting can significantly reduce the number of iterations needed.

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