3207. Maximum Points After Enemy Battles

Problem Link

Description

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You are given an integer array enemyEnergies denoting the energy values of various enemies.

You are also given an integer currentEnergy denoting the amount of energy you have initially.

You start with 0 points, and all the enemies are unmarked initially.

You can perform either of the following operations zero or multiple times to gain points:

• Choose an unmarked enemy, i, such that currentEnergy >= enemyEnergies[i]. By choosing this option:

  <ul>
  	<li>You gain 1 point.</li>
  	<li>Your energy is reduced by the enemy&#39;s energy, i.e. <code>currentEnergy = currentEnergy - enemyEnergies[i]</code>.</li>
  </ul>
  </li>
  <li>If you have <strong>at least</strong> 1 point, you can choose an <strong>unmarked</strong> enemy, <code>i</code>. By choosing this option:
  <ul>
  	<li>Your energy increases by the enemy&#39;s energy, i.e. <code>currentEnergy = currentEnergy + enemyEnergies[i]</code>.</li>
  	<li>The <font face="monospace">e</font>nemy <code>i</code> is <strong>marked</strong>.</li>
  </ul>
  </li>
  

Return an integer denoting the maximum points you can get in the end by optimally performing operations.

 

Example 1:

Input: enemyEnergies = [3,2,2], currentEnergy = 2

Output: 3

Explanation:

The following operations can be performed to get 3 points, which is the maximum:

• First operation on enemy 1: points increases by 1, and currentEnergy decreases by 2. So, points = 1, and currentEnergy = 0.
• Second operation on enemy 0: currentEnergy increases by 3, and enemy 0 is marked. So, points = 1, currentEnergy = 3, and marked enemies = [0].
• First operation on enemy 2: points increases by 1, and currentEnergy decreases by 2. So, points = 2, currentEnergy = 1, and marked enemies = [0].
• Second operation on enemy 2: currentEnergy increases by 2, and enemy 2 is marked. So, points = 2, currentEnergy = 3, and marked enemies = [0, 2].
• First operation on enemy 1: points increases by 1, and currentEnergy decreases by 2. So, points = 3, currentEnergy = 1, and marked enemies = [0, 2].

Example 2:

Input: enemyEnergies = [2], currentEnergy = 10

Output: 5

Explanation:

Performing the first operation 5 times on enemy 0 results in the maximum number of points.

 

Constraints:

• 1 <= enemyEnergies.length <= 105
• 1 <= enemyEnergies[i] <= 109
• 0 <= currentEnergy <= 109

Solution

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Python3

class Solution:
    def maximumPoints(self, A: List[int], currentEnergy: int) -> int:
        N = len(A)
        A.sort()
        res = 0
        i, j = 0, N - 1
        
        while i <= j:
            if currentEnergy >= A[i]:
                take = currentEnergy // A[i]
                currentEnergy -= take * A[i]
                res += take
            else:
                if res == 0: break
                
                currentEnergy += A[j]
                j -= 1
        
        return res