2578. Split With Minimum Sum

Problem Link

Description

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Given a positive integer num, split it into two non-negative integers num1 and num2 such that:

• The concatenation of num1 and num2 is a permutation of num.

  <ul>
  	<li>In other words, the sum of the number of occurrences of each digit in <code>num1</code> and <code>num2</code> is equal to the number of occurrences of that digit in <code>num</code>.</li>
  </ul>
  </li>
  <li><code>num1</code> and <code>num2</code> can contain leading zeros.</li>
  

Return the minimum possible sum of num1 and num2.

Notes:

• It is guaranteed that num does not contain any leading zeros.
• The order of occurrence of the digits in num1 and num2 may differ from the order of occurrence of num.

 

Example 1:

Input: num = 4325
Output: 59
Explanation: We can split 4325 so that num1 is 24 and num2 is 35, giving a sum of 59. We can prove that 59 is indeed the minimal possible sum.

Example 2:

Input: num = 687
Output: 75
Explanation: We can split 687 so that num1 is 68 and num2 is 7, which would give an optimal sum of 75.

 

Constraints:

• 10 <= num <= 109

Solution

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Python3

class Solution:
    def splitNum(self, num: int) -> int:
        s = list(map(int, str(num)))
        N = len(s)
        s.sort()
        first = second = 0
        
        for i in range(N):
            if i % 2 == 0:
                first = first * 10 + s[i]
            else:
                second = second * 10 + s[i]
        
        return first + second