Harder Array Loop Practice

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Array Loop Practice asked for the smallest number in an array, but can solve a harder question?

Challenge

You are given ar, an array of numbers, and need to print the second smallest number in the array. You can modify your solution to Array Loop Practice to find the desired number. Different solutions are possible...

Challenge

Print the second smallest number in an array.

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Comments

Keyana K
Nov 4, 8:18 PM

Its reading my < symbol as a > symbol
Tyler Pond
Nov 22, 6:02 PM

If anybody needs help, take a look at this solution using the bubble sort algorithm.
calo
Jan 13, 8:02 PM

hmmm cant help it, no idea ..is there easier way than "this solution"?
Learneroo
Jan 13, 9:08 PM

@calo, this problem can be solved much in a much simpler manner. See the hint that I added to the problem.
Victoria Holland
Jan 14, 12:45 PM

I got there in the end! This is the link to my answer: http://www.learneroo.com/user_answers/0675578220
Learneroo
Jan 14, 3:57 PM

@Victoria, well done! When you learn how to create your own methods, you'll be able to improve it further to avoid code duplication.
Ksenia Sukmanskaya
Jan 23, 7:46 AM

I think that solutions given on links above are far from perfection, since they change the data of the array
Learneroo
Jan 23, 9:10 AM

@Ksenia, that's OK in this challenge. Another approach would be to just track the 2 smallest numbers in the array as you go through it..
Tiago Sirious
Jan 28, 8:46 AM

If you use the way shown in the Hint, be sure to declare your "secondsmallest" variable AFTER changing the smaller variable to a bigger number. Otherwise inputs 1 and 3 wont work!
Btw, thanks to @Victoria Holland, I understood the hint trough her example.
Robin Elliott
Feb 3, 6:41 PM

I get the three numerical outputs green but it still says incorrect ("Your Output" is in red). Is it running some other checks that aren't being announced?
Learneroo
Feb 3, 6:50 PM

@Robin, yes, it often runs on other cases and only shows the overall result for them.
Robin Elliott
Feb 3, 10:26 PM

I finally got it! Though I feel like I cheated a bit by setting my 2nd-smallest variable to an unreasonably high number to begin with, rather than setting it to a value drawn from the array itself. It's here: http://www.learneroo.com/user_answers/8850767557

cont...
(P.S. Please tell me that Java has a way to automatically return the second-smallest number from an array. I'd hate to actually have to use this sort of stuff in production code.)
Learneroo
Feb 3, 11:32 PM

Setting it to a large number is fine, though you could have also selected a number from the array. Java doesn't have any built-in way to do it, though maybe it could be done a little cleaner.

cont...
See also the featured submissions for this challenge.

Cliff Karlsson

Feb 18, 4:37 AM

why does not this work?

int smallest = ar[0];
int secondSmallest = ar[0];

    for(int i=0; i<ar.length; i++){
        if(ar[i] <= smallest){
            secondSmallest=smallest;
            smallest=ar[i];
        }
    }
    System.out.print(secondSmallest);
}

Dino Šišić
Feb 20, 8:32 AM

Here is the solution for the unpatient ones:

static void doStuff(int[] ar){
int x = Integer.MAX_VALUE;
int y = Integer.MAX_VALUE;

// Loop over the array
cont...
for (int i = 0; i < ar.length; i++) { if (ar[i] < x) { y = x; x = ar[i]; } else if (ar[i] < y){ y = ar[i]; } } System.out.println(y);

}
David
Mar 2, 12:53 AM

Took me all day today and i think a little of yesterday to figure this exercise out.

//your code here
//Modified the code to comply this exercise with the input provided
cont...
//however my logic is crashing on how to initiallize the //secondSmallest and how to define it if all //variables in the array are of the same value does the //variable become null? say -> ar[]={8, 8, 8, 8}

Never mind to answer i guess after further lessons i'll prob get to know, this is just for those people out there that go through this exercise without landing on the dot and don't want to "cheat", the exercise is made to comply with scenario provided, meaning input given at the botton, period!

Anyway gotta thank Learneroo for helping noobs like me : )
Jordan Bouvier
Apr 3, 4:59 PM

Here's an example without "cheating" by having to pick an absurdly large number:
http://www.learneroo.com/user_answers/6675108810

許友誠

May 5, 12:02 PM

static void doStuff(int[] ar)
{
    Arrays.sort(ar);
    System.out.println(ar[1]);  //your code here
}

John Slow
Jun 23, 2:53 PM

@Dino Šišić : there is a better solution that doesnt require using integer.Max value (using this would make the problem trivial). Also, there must be no repeating value in the array

Julian

Jul 4, 7:39 AM

    int smallest = ar[0];
    for(int i = 1; i < ar.length; i++){
        if(ar[i] < smallest){
            smallest = ar[i];
        }
    }

    int second = smallest;

cont...

    boolean match = false;

    for(int i = 0; i < ar.length; i++){
        if(!match){
            if(ar[i] > smallest){
                second = ar[i];
                match = true;
            }
        }   
        else{
            if((ar[i] < second) && ar[i] > smallest){
                second = ar[i];
            }
        }
    }
    System.out.println(second);

loupams
Jul 16, 2:22 AM

Another solution:
http://www.learneroo.com/user_answers/1556388287

Vikesh Kumar Sharma

Jul 30, 10:52 AM

it might not be the best solution
int small = ar[0];
int large = ar[0];
int index = 0;
int repeat = 0;

    while(repeat<2)
    {
        for(int i = 0; i < ar.length; i++)

cont...

        {
            if(small>ar[i])
            {
                small = ar[i];
                index = i;
            }

            if(large<ar[i])
            {
                large = ar[i];
            }


        }

        ar[index] = large;

        if(repeat<1)
        small = ar[0];
        repeat++;
    }   

    System.out.println(small);

Macro

Aug 18, 10:39 PM

static void doStuff(int[] ar){
    //your code here
    int[] small = new int[2];
    small[0] = ar[0];
    small[1] = ar[1];
    if(small[0] > small[1]){

cont...

        int t = small[0];
        small[0] = small[1];
        small[1] = t;
    }
    for(int i = 2; i < ar.length; i++){
        if(ar[i] < small[1]){
            small[1] = ar[i];
            if(small[0] > small[1]){
                int q = small[0];
                small[0] = small[1];
                small[1] = q;
            }

        }
    }
    System.out.println(small[1]);
}

Jake Levenson
Sep 6, 2:32 PM

Keep the previous code to find the smallest number, and after that code, add the exact same thing over again with a second condition stating that the cell cannot be equal to the smallest number.

Corey Sheely

Sep 30, 1:45 AM

Can anyone tell me why this won't work?

static void doStuff(int[] ar){
int smallest = ar[0];
for(int i=0; i<ar.length; i=i+1){
    if(ar[i]<smallest){

cont...

        ar[i]=smallest;
        }
    }
int largest=0;
for(int i=0; i<ar.length; i=i+1){
    if(largest<ar[i]){
        ar[i]=largest;
        }//your code here
}

smallest=largest;

int second_smallest = ar[0];
for(int i=0; i<ar.length; i=i+1){
    if(ar[i]<second_smallest){
        ar[i]=second_smallest;
    }
}
System.out.print(second_smallest);

}

Learneroo
Sep 30, 10:14 AM

@corey ar[i]=smallest; will modify the value in the array, is that really what you want to do?

Gaetano

Oct 25, 12:25 AM

Literally tried this for 5 hours without trying to use Google as help, What am i doing wrong here?

import java.util.*;
public class Main{
static void doStuff(int[] ar){

cont...

int smallest = ar[0];
for(int i=0; i < ar.length; i = i+1){
    if(ar[i] < smallest){
    smallest = ar[i];
    }
    }
int small = ar[0];
for(int i=0; i < ar.length; i = i+1){
if(ar[i] < small && ar[i] != smallest){
    small = ar[i];
    }
    }
    System.out.println(small);
}

Learneroo
Oct 25, 7:46 PM

@Gaetano, step through your code with the examples that are wrong to spot the error. For example, what happens when your code runs on the first case? Consider changing the smallest numbers so it doesn't cause trouble the second time...
thales
Jul 13, 8:13 AM

It took me a while (from int i = one a clock; i= two o clock; i++) :-) but i think i found it.
Here is my answer.

my code