How hard is LeetCode 2838. Maximum Coins Heroes Can Collect?

LeetCode 2838. Maximum Coins Heroes Can Collect is rated Medium on LeetCode.

What is the time complexity of LeetCode 2838. Maximum Coins Heroes Can Collect?

The Python solution on this page runs in O((m + n) \times \log n).

What is the space complexity of LeetCode 2838. Maximum Coins Heroes Can Collect?

The Python solution on this page uses O(m) auxiliary space.

What topics does LeetCode 2838. Maximum Coins Heroes Can Collect cover?

LeetCode 2838. Maximum Coins Heroes Can Collect is tagged Array, Two Pointers, Binary Search, Prefix Sum and Sorting on LeetCode.

Is LeetCode 2838. Maximum Coins Heroes Can Collect a premium problem?

Yes. LeetCode 2838. Maximum Coins Heroes Can Collect is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.

Maximum Coins Heroes Can Collect — LeetCode 2838 Python Solution

MediumLeetCode PremiumArrayTwo PointersBinary SearchPrefix SumSorting

Problem: #2838
Pattern: Prefix Sum
Reading time: 3 min
Source: leetcode.com

The problem

There is a battle and n heroes are trying to defeat m monsters. You are given two 1-indexed arrays of positive integers heroes and monsters of length n and m, respectively.

Example

Input: heroes = [1,4,2], monsters = [1,1,5,2,3], coins = [2,3,4,5,6]
Output: [5,16,10]
Explanation: For each hero, we list the index of all the monsters he can defeat:

Python solution

Python

class Solution:
    def maximumCoins(
        self, heroes: List[int], monsters: List[int], coins: List[int]
    ) -> List[int]:
        m = len(monsters)
        idx = sorted(range(m), key=lambda i: monsters[i])
        s = list(accumulate((coins[i] for i in idx), initial=0))
        ans = []
        for h in heroes:
            i = bisect_right(idx, h, key=lambda i: monsters[i])
            ans.append(s[i])
        return ans

Complexity

Measure	Complexity
Time	O((m + n) \times \log n)
Space	O(m) auxiliary

Pattern: Prefix Sum

Precompute running totals once so any range query becomes a single subtraction. LeetCode 2838. Maximum Coins Heroes Can Collect is filed here because LeetCode tags it Prefix Sum, which is the vocabulary this hub collects.

The prefix sum guide has the Python template for the pattern and the 157 LeetCode problems that use it.

Frequently asked questions

How hard is LeetCode 2838. Maximum Coins Heroes Can Collect?: LeetCode 2838. Maximum Coins Heroes Can Collect is rated Medium on LeetCode.
What is the time complexity of LeetCode 2838. Maximum Coins Heroes Can Collect?: The Python solution on this page runs in O((m + n) \times \log n).
What is the space complexity of LeetCode 2838. Maximum Coins Heroes Can Collect?: The Python solution on this page uses O(m) auxiliary space.
What topics does LeetCode 2838. Maximum Coins Heroes Can Collect cover?: LeetCode 2838. Maximum Coins Heroes Can Collect is tagged Array, Two Pointers, Binary Search, Prefix Sum and Sorting on LeetCode.
Is LeetCode 2838. Maximum Coins Heroes Can Collect a premium problem?: Yes. LeetCode 2838. Maximum Coins Heroes Can Collect is a LeetCode Premium problem, so the full statement and test cases require a paid LeetCode subscription.