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Thread: recursion problem, please help

  1. #1
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    Default recursion problem, please help

    I need to write a code that recieve an integer and find whether it forms an ascending series or not.
    for example:
    123 - true
    2579 - true
    321 - false
    1338 - false
    222 - false
    5 - true

    I wrote this recursion but i don't get the right result
    can someone tell me what's wrong with it please?
    Thanks...

    private static boolean numCheck(int num) {
     
    		if ((num/10) == 0) {
    			return true;
    		} else {
    			if ((num % 10) > ((num/10) % 10)) {
    				numCheck(num/10);
    			} else {
    				return false;
    			}
    		}
     
    	}
    Last edited by helloworld922; October 18th, 2010 at 04:33 PM.

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    javapenguin (October 18th, 2010)


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    Default Re: recursion problem, please help

    What result do you get instead? What should the algorithm do?

    Post an SSCCE that demonstrates the problem, and we'll go from there.

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    Default Re: recursion problem, please help

    Quote Originally Posted by nil View Post
    I need to write a code that recieve an integer and find whether it forms an ascending series or not.
    for example:
    123 - true
    2579 - true
    321 - false
    1338 - false
    222 - false
    5 - true

    I wrote this recursion but i don't get the right result
    can someone tell me what's wrong with it please?
    Thanks...


    private static boolean numCheck(int num) {

    if ((num/10) == 0) {
    return true;
    } else {
    if ((num % 10) > ((num/10) % 10)) {
    numCheck(num/10);
    } else {
    return false;
    }
    }

    }
    I can't see anything wrong, unless you're entering negative values.



    123%10 = 3

    123/10 = 12;

    12%10 = 2;

    3 > 2;

    numCheck(12);

    12%10 = 2;

    12/10 = 1;

    1%10 = 1;

    2 > 1;

    numCheck(1);

    1/10 = 0;

    return true;

    122%10 = 2;

    122/10 = 12;

    12%10 = 2;

    2 = 2;

    return false;
    Last edited by javapenguin; October 18th, 2010 at 02:06 PM.

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