[LeetCode]#1281. Subtract the Product and Sum of Digits of an Integer

Environment: Python 3.7

Key technique: for loop

Given an integer number n, return the difference between the product of its digits and the sum of its digits.

Example 1:

Input: n = 234
Output: 15 
Explanation: 
Product of digits = 2 * 3 * 4 = 24 
Sum of digits = 2 + 3 + 4 = 9 
Result = 24 - 9 = 15

Example 2:

Input: n = 4421
Output: 21
Explanation: 
Product of digits = 4 * 4 * 2 * 1 = 32 
Sum of digits = 4 + 4 + 2 + 1 = 11 
Result = 32 - 11 = 21

Constraints:

• 1 <= n <= 10^5

Analysis:

There are two step for solving this issue.

1. Convert int into string for extracting each number.
2. Convert string into int for calculating product and sum.

Solution:

class Solution:
  def subtractProductAndSum(self, n):
      str_n=str(n)
      p=1
      sum_n = 0
      for i in str_n:
          p *= int(i)
          sum_n += int(i)
            
      return p - sum_n

Submitted result:

Reference:

https://leetcode.com/problems/subtract-the-product-and-sum-of-digits-of-an-integer/discuss/574702/24ms-Python3-Solution