1837

1837. Sum of Digits in Base K (Easy)

Given an integer n (in base 10) and a base k, return the sum of the digits of n after converting n from base 10 to base k.

After converting, each digit should be interpreted as a base 10 number, and the sum should be returned in base 10.

 

Example 1:

Input: n = 34, k = 6
Output: 9
Explanation: 34 (base 10) expressed in base 6 is 54. 5 + 4 = 9.

Example 2:

Input: n = 10, k = 10
Output: 1
Explanation: n is already in base 10. 1 + 0 = 1.

 

Constraints:

• 1 <= n <= 100
• 2 <= k <= 10

Related Topics:
Math, Bit Manipulation

Solution 1.

// OJ: https://leetcode.com/problems/sum-of-digits-in-base-k/
// Author: github.com/lzl124631x
// Time: O(log_K(N))
// Space: O(1)
class Solution {
public:
    int sumBase(int n, int k) {
        int ans = 0;
        for (; n; n /= k) {
            ans += n % k;
        }
        return ans;
    }
};