1658. Minimum Operations to Reduce X to Zero
Minimum Operations to Reduce X to Zero (LeetCode 1658) is a Medium Data Structures and Algorithms interview problem you can solve, run and submit on Thita.ai. It belongs to the Sliding Window pattern, in the Variable Size (Condition-Based) subpattern.
How to solve Minimum Operations to Reduce X to Zero
Minimum Operations to Reduce X to Zero is a Variable Size Sliding Window problem, part of Sliding Window. Master variable-size sliding window for condition-based problems like longest substring without repeating characters.
Work towards the solution in these steps:
- Think in reverse; instead of finding the minimum prefix + suffix, find the maximum subarray.
- Finding the maximum subarray is standard and can be done greedily.
The reference solution runs in O(n) time and O(1) space.
The Minimum Operations to Reduce X to Zero solution and editorial walks through the full approach with reference code.
Problem statement
You are given an integer array nums and an integer x. In one operation, you can either remove the leftmost or the rightmost element from the array nums and subtract its value from x. Note that this modifies the array for future operations.
Return the minimum number of operations to reduce x to exactly 0 if it is possible, otherwise, return -1.
Example 1:
Input: nums = [1,1,4,2,3], x = 5 Output: 2 Explanation: The optimal solution is to remove the last two elements to reduce x to zero.
Example 2:
Input: nums = [5,6,7,8,9], x = 4 Output: -1
Example 3:
Input: nums = [3,2,20,1,1,3], x = 10 Output: 5 Explanation: The optimal solution is to remove the last three elements and the first two elements (5 operations in total) to reduce x to zero.
Constraints:
- 1 <= nums.length <= 105
- 1 <= nums[i] <= 104
- 1 <= x <= 109
Topics and companies
Topics: Array, Hash Table, Binary Search, Sliding Window, Prefix Sum.
Reported in interviews at Google.
How to practise Minimum Operations to Reduce X to Zero on Thita.ai
Starter code is provided in C, C#, C++, Go, Java, JavaScript and Python. Your solution runs against 5 test cases for this problem, with the AI coach available for a hint when you are stuck rather than a finished answer. The reference solution runs in O(n) time and O(1) space.
Open Minimum Operations to Reduce X to Zero in the code editor, or read the Minimum Operations to Reduce X to Zero editorial for a worked solution with its approach and complexity analysis.
Where Minimum Operations to Reduce X to Zero sits in the DSA pattern sheet
Problems related to Minimum Operations to Reduce X to Zero
Other problems that use the same Variable Size (Condition-Based) and Sliding Window techniques:
- Contains Duplicate II — Easy, same subpattern
- Continuous Subarrays — Medium, same subpattern
- Find Longest Special Substring That Occurs Thrice I — Medium, same subpattern
- Frequency of the Most Frequent Element — Medium, same subpattern
- Fruit Into Baskets — Medium, same subpattern
- Jump Game VII — Medium, same subpattern
Minimum Operations to Reduce X to Zero FAQ
What is the LeetCode number of Minimum Operations to Reduce X to Zero?
Minimum Operations to Reduce X to Zero is LeetCode problem 1658, rated Medium.
What pattern is used to solve Minimum Operations to Reduce X to Zero?
Minimum Operations to Reduce X to Zero is a Variable Size Sliding Window problem. It belongs to the Sliding Window pattern, in the Variable Size (Condition-Based) subpattern.
What is the time complexity of Minimum Operations to Reduce X to Zero?
The reference solution runs in O(n) time and O(1) space.
Which companies ask Minimum Operations to Reduce X to Zero?
Minimum Operations to Reduce X to Zero has been reported in interviews at Google.