#1648

Sell Diminishing-Valued Colored Balls

Medium
ArrayMathBinary SearchGreedySortingHeap (Priority Queue)HeapGreedy
LeetCode ↗

Approaches

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

Intuition

Time O(n log n + orders log n)Space O(n)

The optimal solution uses a greedy approach combined with a priority queue (max-heap) to efficiently sell the highest valued balls first while keeping track of the remaining orders. This significantly reduces the time complexity.

⚙️

Algorithm

4 steps
  1. 1Step 1: Use a max-heap to store the inventory counts.
  2. 2Step 2: While there are orders to fulfill, extract the maximum value from the heap.
  3. 3Step 3: Calculate how many balls can be sold at that value and update the total value accordingly.
  4. 4Step 4: If there are remaining balls of that value, push the new value back into the heap.
solution.py13 lines
1import heapq
2
3def maxProfit(inventory, orders):
4    inventory = [-x for x in inventory]
5    heapq.heapify(inventory)
6    total_value = 0
7    while orders > 0:
8        max_value = -heapq.heappop(inventory)
9        total_value += max_value
10        orders -= 1
11        if max_value - 1 > 0:
12            heapq.heappush(inventory, -(max_value - 1))
13    return total_value % (10**9 + 7)

Complexity note: The complexity is O(n log n) for building the max-heap and O(orders log n) for processing each order, making it efficient for larger inputs.

  • 1Greedily sell the highest valued balls first.
  • 2Using a max-heap allows efficient retrieval of the maximum value.

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