Super Digit
MediumP3Coding
The super digit of a number is defined recursively: if it has one digit, that digit is its super digit; otherwise it is the super digit of the sum of its digits.
You are given n as a string of digits and an integer k. Form the number p by writing n exactly k times in a row, and return the super digit of p.
For example, n = "9875" and k = 2 gives p = 98759875.
Example 1
- Input
- n = "9875", k = 4
- Output
- 8
- Why
- p = 9875987598759875, digit sum 116, then 8.
Example 2
- Input
- n = "148", k = 3
- Output
- 3
- Why
- p = 148148148, digit sum 30, then 3.
Example 3
- Input
- n = "123", k = 3
- Output
- 9
Constraints
- 1 <= n.length <= 100,
ncontains only digits and has no leading zero - 1 <= k <= 10^5
Hints
Give it a real attempt first. Run shows which examples fail.
Saved automatically
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