Minimum Sum of Four Digit Number After Splitting Digits Python/Java solution

In Python or Java, extract digits using modulo and division, store them in a list or array, sort the digits, then compute (10*d0 + d2) + (10*d1 + d3). The implementation is only a few lines because the greedy arrangement directly gives the minimal sum.

What is the best approach for Minimum Sum of Four Digit Number After Splitting Digits?

The optimal approach uses greedy sorting. Extract the four digits, sort them, and distribute the smallest digits into the tens place of two numbers. After sorting digits d0 ≤ d1 ≤ d2 ≤ d3, construct numbers (10*d0 + d2) and (10*d1 + d3). This ensures the smallest digits contribute to the highest positional value, minimizing the total sum.

Is Minimum Sum of Four Digit Number After Splitting Digits asked at Google/Amazon/Meta?

This problem represents a typical easy-level greedy and digit manipulation pattern. Variations of digit rearrangement and greedy placement frequently appear in interviews at companies like Amazon and Google, especially in early screening rounds or coding assessments.

What data structure is used in Minimum Sum of Four Digit Number After Splitting Digits?

The solution typically uses a small array or list to store the digits of the number. After extracting digits with modulo and division operations, the array is sorted and used to construct the two resulting numbers.

What is the time complexity of Minimum Sum of Four Digit Number After Splitting Digits?

The greedy solution runs in O(d log d) time due to sorting the digits, where d is the number of digits. Since the problem always has four digits, this effectively becomes constant time in practice. Space complexity is O(1) because only a small fixed array of digits is stored.

Description Hints 3 Solution Video 6:36

2160. Minimum Sum of Four Digit Number After Splitting Digits

Q: Is Minimum Sum of Four Digit Number After Splitting Digits easy or hard?

LeetCode classifies this problem as Easy. The challenge mainly tests basic digit manipulation, sorting, and recognizing a greedy placement strategy rather than complex data structures or algorithms.

Q: How to solve Minimum Sum of Four Digit Number After Splitting Digits in O(n)?

Since there are only four digits, you can treat the problem as constant time. In a generalized version with more digits, you would extract digits in O(n) and sort them in O(n log n). After sorting, greedily distribute digits between the two numbers to balance place values and minimize the sum.

Easy86.2% acceptance2 companies

You are given a positive integer num consisting of exactly four digits. Split num into two new integers new1 and new2 by using the digits found in num. Leading zeros are allowed in new1 and new2, and all the digits found in num must be used.

For example, given num = 2932, you have the following digits: two 2's, one 9 and one 3. Some of the possible pairs [new1, new2] are [22, 93], [23, 92], [223, 9] and [2, 329].

Return the minimum possible sum of new1 and new2.

Example 1:

Input: num = 2932
Output: 52
Explanation: Some possible pairs [new1, new2] are [29, 23], [223, 9], etc.
The minimum sum can be obtained by the pair [29, 23]: 29 + 23 = 52.

Example 2:

Input: num = 4009
Output: 13
Explanation: Some possible pairs [new1, new2] are [0, 49], [490, 0], etc. 
The minimum sum can be obtained by the pair [4, 9]: 4 + 9 = 13.

Constraints:

1000 <= num <= 9999

Asked at 2 companies

Amazon Meta

Topics

Hints open one at a time

Hint 1

Notice that the most optimal way to obtain the minimum possible sum using 4 digits is by summing up two 2-digit numbers.

Hint 2

We can use the two smallest digits out of the four as the digits found in the tens place respectively.

Hint 3

Similarly, we use the final 2 larger digits as the digits found in the ones place.

6:36

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