Sync LeetCode submission Runtime - 26 ms (96.34%), Memory - 34.2 MB (62.20%)

Author: jimit105

2674-make-the-prefix-sum-non-negative/README.md

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+<p>You are given a <strong>0-indexed</strong> integer array <code>nums</code>. You can apply the following operation any number of times:</p>
+
+<ul>
+	<li>Pick any element from <code>nums</code> and put it at the end of <code>nums</code>.</li>
+</ul>
+
+<p>The prefix sum array of <code>nums</code> is an array <code>prefix</code> of the same length as <code>nums</code> such that <code>prefix[i]</code> is the sum of all the integers <code>nums[j]</code> where <code>j</code> is in the inclusive range <code>[0, i]</code>.</p>
+
+<p>Return <em>the minimum number of operations such that the prefix sum array does not contain negative integers</em>. The test cases are generated such that it is always possible to make the prefix sum array non-negative.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [2,3,-5,4]
+<strong>Output:</strong> 0
+<strong>Explanation:</strong> we do not need to do any operations.
+The array is [2,3,-5,4]. The prefix sum array is [2, 5, 0, 4].
+</pre>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<pre>
+<strong>Input:</strong> nums = [3,-5,-2,6]
+<strong>Output:</strong> 1
+<strong>Explanation:</strong> we can do one operation on index 1.
+The array after the operation is [3,-2,6,-5]. The prefix sum array is [3, 1, 7, 2].
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= nums.length &lt;= 10<sup>5</sup></code></li>
+	<li><code>-10<sup>9</sup> &lt;= nums[i] &lt;= 10<sup>9</sup></code></li>
+</ul>

2674-make-the-prefix-sum-non-negative/solution.py

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+# Approach: Greedy
+
+# Time: O(n log n)
+# Space: O(n)
+
+import heapq
+
+class Solution:
+    def makePrefSumNonNegative(self, nums: List[int]) -> int:
+        operations = 0
+        prefix_sum = 0
+        pq = []
+
+        for num in nums:
+            # Push negative numbers to min heap
+            if num < 0:
+                heapq.heappush(pq, num)
+
+            prefix_sum += num
+
+            # Pop minimum element from heap and subtract from sum
+            if prefix_sum < 0:
+                prefix_sum -= heapq.heappop(pq)
+                operations += 1
+
+        return operations