## CCCHK '08 J2 - Lucky Number

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Points: 3
Time limit: 1.0s
Memory limit: 64M

Problem type

In ancient Europe, people believed that their luck was dependent on a number. By summing up the digits of their birthday, they got a sum. By repeatedly adding the digits of the sum until a single digit number remains. This resultant number was called the "single digit representation". And the digit reflected their luck in their whole life.

In this question, a birthday will be given by a non-negative integer ( digits). Your program has to compute the single digit representation of the given number. Example:

#### Input Specification

The first input is an integer specifying the number of test cases. Then each input number appears on a line by itself.

#### Output Specification

For each test case, output the single digit representation of it.

#### Sample Input

4
1
10
19
999

#### Sample Output

1
1
1
9

• commented on Dec. 10, 2022, 7:59 p.m.

This kind of number is better known as "digital root" (999, anyone?)

• commented on Aug. 27, 2019, 7:19 p.m.

Why do I keep getting IRs?

• commented on Aug. 27, 2019, 8:22 p.m. edit 2

The input integers can be up to digits long. Integer.parseInt() cannot parse integers from the input greater than .

And in fact you cannot store a digit number as an int or even a long. Consider storing it as a String.

• commented on March 14, 2017, 3:40 p.m. edited

This comment is hidden due to too much negative feedback. Show it anyway.

• commented on March 14, 2017, 4:30 p.m.

You're trying to read an integer of maximum length digits. That's far greater than the max value of an int.

• commented on Aug. 1, 2021, 10:18 p.m.

oh. I didn't know that. Thank you!