You are given a positive integer n. Each digit of n has a sign according to the following rules:
- The most significant digit is assigned a positive sign.
- Each other digit has an opposite sign to its adjacent digits.
Return the sum of all digits with their corresponding sign.
Example 1:
Input: n = 521
Output: 4
Explanation: (+5) + (-2) + (+1) = 4.
Example 2:
Input: n = 111
Output: 1
Explanation: (+1) + (-1) + (+1) = 1.
Example 3:
Input: n = 886996
Output: 0
Explanation: (+8) + (-8) + (+6) + (-9) + (+9) + (-6) = 0.
Solution
class Solution:
def alternateDigitSum(self, n: int) -> int:
out = 0
n = str(n)
for i in range(0, len(n), 2):
out += int(n[i])
for j in range(1, len(n), 2):
out -= int(n[j])
return out