Is Find the Sum of Encrypted Integers easy or hard?

Find the Sum of Encrypted Integers is classified as an Easy problem on LeetCode with a high acceptance rate around 74%. It focuses on basic array traversal and digit manipulation rather than advanced data structures or algorithms.

Find the Sum of Encrypted Integers Python/Java solution

In Python or Java, loop through each number, compute the maximum digit using a while loop with modulo operations, count the digits, and build the encrypted value by repeatedly multiplying by 10 and adding the max digit. Sum these encrypted numbers to produce the final result.

How to solve Find the Sum of Encrypted Integers in O(n)?

Treat the digit length as a small constant. For each array element, extract digits using modulo and division to determine the maximum digit and length, then construct the encrypted number like 777 or 9999. The array is scanned once, giving O(n · d) time which behaves like O(n) for typical integer sizes.

What is the best approach for Find the Sum of Encrypted Integers?

The best approach iterates through each number, finds the maximum digit, counts its digits, and rebuilds a number consisting only of that digit repeated. This iterative digit transformation runs in O(n · d) time where d is the number of digits per number, and uses O(1) extra space.

Is Find the Sum of Encrypted Integers asked at Google/Amazon/Meta?

The problem itself is a LeetCode Easy question and is more common in screening rounds or practice sets rather than direct Google or Meta interview questions. However, the underlying skill—digit manipulation and number reconstruction—appears in many coding interviews.

What data structure is used in Find the Sum of Encrypted Integers?

The main structure is an array that stores the input numbers. The algorithm relies on basic math operations such as modulo (%) and integer division to extract digits rather than additional data structures.

What is the time complexity of Find the Sum of Encrypted Integers?

The time complexity is O(n · d). Each of the n integers is processed digit by digit, and a number with d digits requires at most d operations to find the maximum digit and rebuild the encrypted value. Space complexity remains O(1).

Description Hints 1 Solution Video 0:17

3079. Find the Sum of Encrypted Integers

Easy74.7% acceptance1 company

You are given an integer array nums containing positive integers. We define a function encrypt such that encrypt(x) replaces every digit in x with the largest digit in x. For example, encrypt(523) = 555 and encrypt(213) = 333.

Return the sum of encrypted elements.

Example 1:

Input: nums = [1,2,3]

Output: 6

Explanation: The encrypted elements are [1,2,3]. The sum of encrypted elements is 1 + 2 + 3 == 6.

Example 2:

Input: nums = [10,21,31]

Output: 66

Explanation: The encrypted elements are [11,22,33]. The sum of encrypted elements is 11 + 22 + 33 == 66.

Constraints:

1 <= nums.length <= 50
1 <= nums[i] <= 1000

Asked at 1 company

Larsen Toubro

Topics

Array Math

Hints open one at a time

Hint 1

Encrypted numbers are of the form 11…1 * maxDigit.

0:17

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