## CCC '00 J2 - 9966

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Points: 3
Time limit: 1.0s
Memory limit: 256M

Problem type
##### Canadian Computing Competition: 2000 Stage 1, Junior #2

The digits , , and look much the same if rotated degrees on the page (turned upside down). Also, the digit looks much like a , and vice versa, when rotated degrees on the page. A multi-digit number may also look like itself when rotated on the page; for example and do, but and do not.

You are to write a program to count how many numbers from a given interval look like themselves when rotated degrees on the page. For example, in the interval there are six: , , , , , and .

Your program should take as input two integers, and , which define the interval to be checked, . The output from your program is the number of rotatable numbers in the interval.

You may assume that all input is valid.

#### Sample Input

1
100

#### Sample Output

6

• commented on Feb. 11, 2024, 4:24 a.m.

i swear 2000 is the hardest CCC junior

• commented on Feb. 12, 2024, 3:26 a.m.

fr

• commented on Feb. 1, 2024, 7:57 p.m.

nice problem.

• commented on Feb. 1, 2024, 7:52 p.m.

The numbers are 1,6,8,9,0

• commented on Feb. 1, 2024, 7:58 p.m.

redacted

• commented on Oct. 25, 2022, 2:59 a.m. edited

does 2 and 5 work for this question? they do look somewhat similar...

• commented on Oct. 25, 2022, 4:52 p.m.

No, only the numbers listed

• commented on Oct. 25, 2022, 10:39 p.m.

thx

• commented on Jan. 9, 2020, 12:14 a.m. edited

My solution worked but it's way above the memory limit... How would one approach to reduce memory?

• commented on Jan. 9, 2020, 5:16 a.m. edit 2

In Java, the memory displayed is the total memory used by Java itself and your program. However, the memory limit is calculated internally based on what your program actually uses. Java itself takes around 24 megabytes for just "Hello, World!" If you had actually went over the memory limit, you would receive an MLE verdict.

• commented on Aug. 28, 2019, 10:26 p.m.

What are the second, third and fourth test conditions? My code seems to work fine for any number I put in.

• commented on Aug. 28, 2019, 11:33 p.m. edited

Try the following test case:

8008
8008

The expected output is: 1

• commented on Oct. 28, 2022, 5:28 a.m.

tysm :D

• commented on Aug. 29, 2019, 3:06 a.m.

ty very much! I forgot 0 turned upside down is also a 0 smh...

• commented on July 4, 2019, 8:16 p.m.

I'm getting WA for the third and fourth test cases. Are there any conditions (my if/else statements) I missed (or applied to the wrong things)?

• commented on Sept. 28, 2020, 2:21 a.m.

So am I, im not sure why though.

• commented on July 4, 2019, 9:35 p.m. edited

At this for loop: for (int i = 0; i < aString.length()/2; i++){, the condition checks for the length of the string after every iteration, even if its size is changed.

• commented on July 5, 2019, 8:10 p.m.

Oh, I see. Is it possible to make it so that the for loop's condition is dynamic (changes each time)? As you can see in my code, it depends on the string shrinking and it's similar to recursion (although I think it's more simple). Is the only other way I can do it with this approach be using a recursive method?

• commented on June 17, 2019, 4:40 p.m.

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

• commented on June 17, 2019, 5:45 p.m.

Your solution looks quite a bit over complicated my friend. Try to break it down into simpler conditions and test for each one.