本帖最後由 陳育霖 於 2024-4-27 11:06 編輯
11332 Summing Digits
For a positive integer n, let f(n) denote the sum of the digits of n when represented in base 10.It is easy to see that the sequence of numbers n, f(n), f(f(n)), f(f(f(n))), . . . eventually becomes a single digit number that repeats forever. Let this single digit be denoted g(n).
For example, consider n = 1234567892. Then:
f(n) = 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 2 = 47
f(f(n)) = 4 + 7 = 11
f(f(f(n))) = 1 + 1 = 2
Therefore, g(1234567892) = 2.
Input
Each line of input contains a single positive integer n at most 2,000,000,000. Input is terminated by n = 0 which should not be processed.
Output
For each such integer, you are to output a single line
containing g(n).
Sample Input
2
11
47
1234567892
0
Sample Output
2
2
2
2
提示: 字串處理 |
