1281. Subtract the Product and Sum of Digits of an Integer
Description
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
Solutions
Solution 1: Simulation
We use two variables $x$ and $y$ to record the product of the digits and the sum of the digits respectively. At the beginning, $x=1,y=0$.
When $n \gt 0$, each time we take the $mod$ of $n$ by $10$ to get the current digit $v$, and continue the next loop by dividing $n$ by $10$. In each loop, we update $x = x \times v$, $y = y + v$.
Finally, we return $x - y$.
The time complexity is $O(\log n)$, where $n$ is the given integer. The space complexity is $O(1)$.
1 2 3 4 |
|
1 2 3 4 5 6 7 8 9 10 11 |
|
1 2 3 4 5 6 7 8 9 10 11 12 |
|
1 2 3 4 5 6 7 8 9 |
|
1 2 3 4 5 6 7 8 9 |
|
1 2 3 4 5 6 7 8 9 10 11 12 13 |
|
1 2 3 4 5 6 7 8 9 10 11 12 |
|
1 2 3 4 5 6 7 8 9 10 |
|