Sum of Numbers With Units Digit K — LeetCode 2310 Python Solution

The problem

Given two integers num and k, consider a set of positive integers with the following properties: The units digit of each integer is k. The sum of the integers is num.

Example

Input

num = 58, k = 9

Output

2

Explanation

One valid set is [9,49], as the sum is 58 and each integer has a units digit of 9.

Python solution

class Solution:
    def minimumNumbers(self, num: int, k: int) -> int:
        if num == 0:
            return 0
        for i in range(1, num + 1):
            if (t := num - k * i) >= 0 and t % 10 == 0:
                return i
        return -1

Complexity

Pattern: Greedy

Take the locally best option every time — when you can prove that never costs you later. LeetCode 2310. Sum of Numbers With Units Digit K is filed here because LeetCode tags it Greedy, which is the vocabulary this hub collects.

The greedy guide has the Python template for the pattern and the 346 LeetCode problems that use it.

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