题目描述
Given a number N, you need to find if its digital root is prime or not. DigitalRoot of a number is the repetitive sum of its digits until we get a single-digit number.
Eg.DigitalRoot(191)=1+9+1=>11=>1+1=>2
Example 1:
Input:
N = 89
Output:
0
Explanation:
DigitalRoot(89)=>17=>1+7=>8; not a prime.
Example 2:
Input:
N = 12
Output:
1
Explanation:
DigitalRoot(12)=>1+2=>3; a prime number.
Your Task:
You don't need to read input or print anything. Your task is to complete the function digitalRoot() which takes an integer N as an input parameter and return 1 if its digital root is a prime number otherwise return 0.
Expected Time Complexity: O(1)
Expected Auxiliary Space: O(1)
Constraints:
1 <= N <= 10^{4}
输入格式
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输出格式
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