What is the time complexity of Apply Operations to Make All Array Elements Equal to Zero?

The optimal solution for Apply Operations to Make All Array Elements Equal to Zero runs in O(n) time and uses O(1) space. The time complexity is O(n) because we make a single pass through the array, and the space complexity is O(1) since we only use a few extra variables.

What is the brute force solution for Apply Operations to Make All Array Elements Equal to Zero?

The brute force approach for Apply Operations to Make All Array Elements Equal to Zero is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute-force approach involves repeatedly selecting subarrays of size k and decrementing their values until all elements are zero or we can no longer perform operations. This method is straightforward but inefficient. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Apply Operations to Make All Array Elements Equal to Zero?

Apply Operations to Make All Array Elements Equal to Zero uses the following concepts: Array, Prefix Sum. The recommended patterns to study are: Greedy, Sliding Window.

What are the interview tips for Apply Operations to Make All Array Elements Equal to Zero?

Explain your thought process clearly; don't just jump to code. Consider edge cases, such as when k equals the length of the array. Practice recognizing patterns in problems, such as greedy techniques.

What are common mistakes when solving Apply Operations to Make All Array Elements Equal to Zero?

Not considering the effective value after applying decrements. Failing to account for the boundaries of the array when selecting subarrays.

#2772

Apply Operations to Make All Array Elements Equal to Zero

Medium

ArrayPrefix SumGreedySliding Window

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(1)	O(1)

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Intuition

Time O(n)Space O(1)

The optimal solution uses a greedy approach to ensure that we can reduce elements to zero by maintaining a running total of decrements applied to each element. This allows us to determine if we can make all elements zero without explicitly modifying the array.

⚙️

Algorithm

4 steps

1Step 1: Initialize a variable to track the total decrements applied so far.
2Step 2: Loop through the array and for each element, calculate the effective value after considering the total decrements.
3Step 3: If the effective value is greater than the number of decrements that can be applied from that index to the next k elements, return false.
4Step 4: Update the total decrements and continue until the end of the array.

solution.py11 lines

1def canMakeAllZero(nums, k):
2    n = len(nums)
3    total_decrements = 0
4    for i in range(n):
5        if i >= k:
6            total_decrements -= nums[i - k]
7        if nums[i] - total_decrements > 0:
8            total_decrements += nums[i] - total_decrements
9            if total_decrements > nums[i]:
10                return False
11    return True

ℹ

Complexity note: The time complexity is O(n) because we make a single pass through the array, and the space complexity is O(1) since we only use a few extra variables.

1The order of operations matters; always apply decrements from left to right.
2If an element cannot be reduced to zero due to insufficient decrements, return false.

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