Is Largest Number At Least Twice of Others easy or hard?

Largest Number At Least Twice of Others is classified as an Easy problem. It mainly tests basic array traversal, tracking maximum values, and understanding how to reduce comparisons to constant space.

Largest Number At Least Twice of Others Python/Java solution

In Python or Java, iterate through the array while keeping variables for the largest value, second-largest value, and the index of the largest element. After processing all numbers, verify that the largest value is at least twice the second-largest before returning the index.

How to solve Largest Number At Least Twice of Others in O(n)?

Iterate through the array and maintain two values: the largest element and the second-largest element. Update them as you scan each number. After the loop, check if max >= 2 * secondMax. If true, return the index of the maximum; otherwise return -1.

What is the best approach for Largest Number At Least Twice of Others?

The best approach is a single-pass scan that tracks the largest and second-largest values in the array. After the traversal, check whether the maximum value is at least twice the second maximum. This works in O(n) time and O(1) space and avoids unnecessary additional passes or sorting.

Is Largest Number At Least Twice of Others asked at Google/Amazon/Meta?

This problem is categorized as an easy array problem and commonly appears in coding screens or practice sets used by companies like Amazon and Google. Variants of maximum tracking and dominance checks frequently appear in early interview rounds.

What data structure is used in Largest Number At Least Twice of Others?

The problem uses a simple array traversal. No advanced data structures are required; the algorithm only maintains a few variables to track the maximum and second maximum values while iterating through the array.

What is the time complexity of Largest Number At Least Twice of Others?

The optimal solution runs in O(n) time because the array is scanned once while maintaining the largest and second-largest values. Space complexity is O(1) since only a few variables are used regardless of input size.

Description Hints 1 Solution Video 6:54

747. Largest Number At Least Twice of Others

Easy53.4% acceptance4 companies

You are given an integer array nums where the largest integer is unique.

Determine whether the largest element in the array is at least twice as much as every other number in the array. If it is, return the index of the largest element, or return -1 otherwise.

Example 1:

Input: nums = [3,6,1,0]
Output: 1
Explanation: 6 is the largest integer.
For every other number in the array x, 6 is at least twice as big as x.
The index of value 6 is 1, so we return 1.

Example 2:

Input: nums = [1,2,3,4]
Output: -1
Explanation: 4 is less than twice the value of 3, so we return -1.

Constraints:

2 <= nums.length <= 50
0 <= nums[i] <= 100
The largest element in nums is unique.

Asked at 4 companies

Zoho

Google Microsoft Bloomberg

Topics

Array Sorting

Hints open one at a time

Hint 1

Scan through the array to find the unique largest element `m`, keeping track of it's index `maxIndex`. Scan through the array again. If we find some `x != m` with `m < 2*x`, we should return `-1`. Otherwise, we should return `maxIndex`.

6:54

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