Minimum Initial Energy to Finish Tasks — LeetCode 1665 Python Solution

The problem

You are given an array tasks where tasks[i] = [actuali, minimumi]: actuali is the actual amount of energy you spend to finish the ith task. minimumi is the minimum amount of energy you require to begin the ith task.

Example

Input

tasks = [[1,2],[2,4],[4,8]]

Output

8

Explanation

Starting with 8 energy, we finish the tasks in the following order:

Python solution

class Solution:
    def minimumEffort(self, tasks: List[List[int]]) -> int:
        ans = cur = 0
        for a, m in sorted(tasks, key=lambda x: x[0] - x[1]):
            if cur < m:
                ans += m - cur
                cur = m
            cur -= a
        return ans

Complexity

Pattern: Greedy

Take the locally best option every time — when you can prove that never costs you later. LeetCode 1665. Minimum Initial Energy to Finish Tasks is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Greedy.

The greedy guide has the Python template for the pattern and the 346 LeetCode problems that use it.

Related problems