Skip to main content

Command Palette

Search for a command to run...

Solving Leetcode Interviews in Seconds with AI: Count Tested Devices After Test Operations

Updated
3 min read

Introduction

In this blog post, we will explore how to solve the LeetCode problem "2960" using AI. LeetCode is a popular platform for preparing for coding interviews, and with the help of AI tools like Chatmagic, we can generate solutions quickly and efficiently - helping you pass the interviews and get the job offer without having to study for months.

Problem Statement

You are given a 0-indexed integer array batteryPercentages having length n, denoting the battery percentages of n 0-indexed devices. Your task is to test each device i in order from 0 to n - 1, by performing the following test operations: If batteryPercentages[i] is greater than 0: Increment the count of tested devices. Decrease the battery percentage of all devices with indices j in the range [i + 1, n - 1] by 1, ensuring their battery percentage never goes below 0, i.e, batteryPercentages[j] = max(0, batteryPercentages[j] - 1). Move to the next device. Otherwise, move to the next device without performing any test. Return an integer denoting the number of devices that will be tested after performing the test operations in order. Example 1: Input: batteryPercentages = [1,1,2,1,3] Output: 3 Explanation: Performing the test operations in order starting from device 0: At device 0, batteryPercentages[0] > 0, so there is now 1 tested device, and batteryPercentages becomes [1,0,1,0,2]. At device 1, batteryPercentages[1] == 0, so we move to the next device without testing. At device 2, batteryPercentages[2] > 0, so there are now 2 tested devices, and batteryPercentages becomes [1,0,1,0,1]. At device 3, batteryPercentages[3] == 0, so we move to the next device without testing. At device 4, batteryPercentages[4] > 0, so there are now 3 tested devices, and batteryPercentages stays the same. So, the answer is 3. Example 2: Input: batteryPercentages = [0,1,2] Output: 2 Explanation: Performing the test operations in order starting from device 0: At device 0, batteryPercentages[0] == 0, so we move to the next device without testing. At device 1, batteryPercentages[1] > 0, so there is now 1 tested device, and batteryPercentages becomes [0,1,1]. At device 2, batteryPercentages[2] > 0, so there are now 2 tested devices, and batteryPercentages stays the same. So, the answer is 2. Constraints: 1 <= n == batteryPercentages.length <= 100 0 <= batteryPercentages[i] <= 100

Explanation

Here's a breakdown of the solution:

  • Simulate the Process: Iterate through the batteryPercentages array, simulating the described test operations.
  • Track Tested Devices: Maintain a count of the tested devices.
  • Decrement Battery Percentages: When a device is tested, decrement the battery percentages of subsequent devices, ensuring they don't fall below 0.

  • Runtime Complexity: O(n^2), Storage Complexity: O(1)

Code

    def countTestedDevices(batteryPercentages):
    """
    Counts the number of devices tested based on the given battery percentages.

    Args:
        batteryPercentages: A list of integers representing the battery percentages of devices.

    Returns:
        An integer representing the number of devices tested.
    """

    n = len(batteryPercentages)
    tested_devices = 0

    for i in range(n):
        if batteryPercentages[i] > 0:
            tested_devices += 1
            for j in range(i + 1, n):
                batteryPercentages[j] = max(0, batteryPercentages[j] - 1)

    return tested_devices

More from this blog

C

Chatmagic blog

2894 posts