Finding adjacent elements in a 2d array and counting them.











up vote
2
down vote

favorite












Im stumped on what to do for this part of my homework and could really use some help. I need to cycle through a given 2d array and find all similar elements that are adjacent to another and count that so for example



AA--B
AA--B
-AA--
----C


So the count would be 3 one for the As one for the Bs and one for the C, I just kinda need an idea where to start So far i have



public static int howManyOrganisms(char image){
int count = 0;
for (int i = 0; i < image.length; i++) {
for (int j = 0; j < image[i].length; j++) {
if(image[i][j] != '-') {
count++;

}
System.out.println();
}
return howManyOrganisms(image, count);
}
}


I need help figuring out how to track the total number of elements that are within contact of one another (so left, right, down, up) being another similar element.










share|improve this question


















  • 2




    You're on the right track: 1) GOAL: count #/adjacent elements. 2) Define a function. EXAMPLE: howManyOrganisms(). 3) Create some loops to examine every column in every row. 4) For each element, check up, down, right and left. If adjacent to one or more, then add to count. 5) Optimize (do you need to check "up" for 1st row, or "right" for last column, etc).
    – paulsm4
    Nov 19 at 20:22






  • 1




    Seems like a classis 'flood fill' algorithm modification. Check this
    – Victor Gubin
    Nov 19 at 20:33















up vote
2
down vote

favorite












Im stumped on what to do for this part of my homework and could really use some help. I need to cycle through a given 2d array and find all similar elements that are adjacent to another and count that so for example



AA--B
AA--B
-AA--
----C


So the count would be 3 one for the As one for the Bs and one for the C, I just kinda need an idea where to start So far i have



public static int howManyOrganisms(char image){
int count = 0;
for (int i = 0; i < image.length; i++) {
for (int j = 0; j < image[i].length; j++) {
if(image[i][j] != '-') {
count++;

}
System.out.println();
}
return howManyOrganisms(image, count);
}
}


I need help figuring out how to track the total number of elements that are within contact of one another (so left, right, down, up) being another similar element.










share|improve this question


















  • 2




    You're on the right track: 1) GOAL: count #/adjacent elements. 2) Define a function. EXAMPLE: howManyOrganisms(). 3) Create some loops to examine every column in every row. 4) For each element, check up, down, right and left. If adjacent to one or more, then add to count. 5) Optimize (do you need to check "up" for 1st row, or "right" for last column, etc).
    – paulsm4
    Nov 19 at 20:22






  • 1




    Seems like a classis 'flood fill' algorithm modification. Check this
    – Victor Gubin
    Nov 19 at 20:33













up vote
2
down vote

favorite









up vote
2
down vote

favorite











Im stumped on what to do for this part of my homework and could really use some help. I need to cycle through a given 2d array and find all similar elements that are adjacent to another and count that so for example



AA--B
AA--B
-AA--
----C


So the count would be 3 one for the As one for the Bs and one for the C, I just kinda need an idea where to start So far i have



public static int howManyOrganisms(char image){
int count = 0;
for (int i = 0; i < image.length; i++) {
for (int j = 0; j < image[i].length; j++) {
if(image[i][j] != '-') {
count++;

}
System.out.println();
}
return howManyOrganisms(image, count);
}
}


I need help figuring out how to track the total number of elements that are within contact of one another (so left, right, down, up) being another similar element.










share|improve this question













Im stumped on what to do for this part of my homework and could really use some help. I need to cycle through a given 2d array and find all similar elements that are adjacent to another and count that so for example



AA--B
AA--B
-AA--
----C


So the count would be 3 one for the As one for the Bs and one for the C, I just kinda need an idea where to start So far i have



public static int howManyOrganisms(char image){
int count = 0;
for (int i = 0; i < image.length; i++) {
for (int j = 0; j < image[i].length; j++) {
if(image[i][j] != '-') {
count++;

}
System.out.println();
}
return howManyOrganisms(image, count);
}
}


I need help figuring out how to track the total number of elements that are within contact of one another (so left, right, down, up) being another similar element.







java arrays for-loop recursion multidimensional-array






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 19 at 20:15









Forrest Walker

304




304








  • 2




    You're on the right track: 1) GOAL: count #/adjacent elements. 2) Define a function. EXAMPLE: howManyOrganisms(). 3) Create some loops to examine every column in every row. 4) For each element, check up, down, right and left. If adjacent to one or more, then add to count. 5) Optimize (do you need to check "up" for 1st row, or "right" for last column, etc).
    – paulsm4
    Nov 19 at 20:22






  • 1




    Seems like a classis 'flood fill' algorithm modification. Check this
    – Victor Gubin
    Nov 19 at 20:33














  • 2




    You're on the right track: 1) GOAL: count #/adjacent elements. 2) Define a function. EXAMPLE: howManyOrganisms(). 3) Create some loops to examine every column in every row. 4) For each element, check up, down, right and left. If adjacent to one or more, then add to count. 5) Optimize (do you need to check "up" for 1st row, or "right" for last column, etc).
    – paulsm4
    Nov 19 at 20:22






  • 1




    Seems like a classis 'flood fill' algorithm modification. Check this
    – Victor Gubin
    Nov 19 at 20:33








2




2




You're on the right track: 1) GOAL: count #/adjacent elements. 2) Define a function. EXAMPLE: howManyOrganisms(). 3) Create some loops to examine every column in every row. 4) For each element, check up, down, right and left. If adjacent to one or more, then add to count. 5) Optimize (do you need to check "up" for 1st row, or "right" for last column, etc).
– paulsm4
Nov 19 at 20:22




You're on the right track: 1) GOAL: count #/adjacent elements. 2) Define a function. EXAMPLE: howManyOrganisms(). 3) Create some loops to examine every column in every row. 4) For each element, check up, down, right and left. If adjacent to one or more, then add to count. 5) Optimize (do you need to check "up" for 1st row, or "right" for last column, etc).
– paulsm4
Nov 19 at 20:22




1




1




Seems like a classis 'flood fill' algorithm modification. Check this
– Victor Gubin
Nov 19 at 20:33




Seems like a classis 'flood fill' algorithm modification. Check this
– Victor Gubin
Nov 19 at 20:33












1 Answer
1






active

oldest

votes

















up vote
1
down vote













In each iteration, you can use your i,j variables to "navigate" the 2d plane and see if any interacting items are the same. In each iteration you would check the following indexes to see if they are the same:




  • image[i-1][j] (one row up)

  • image[i+1][j] (one row down)

  • image[i][j-1] (one left)

  • image[i][j+1] (one right)


Of course for all of these statements first you should check if +1/-1 is still within the size of your matrix, otherwise you will end up with out of bounds exception.






share|improve this answer





















    Your Answer






    StackExchange.ifUsing("editor", function () {
    StackExchange.using("externalEditor", function () {
    StackExchange.using("snippets", function () {
    StackExchange.snippets.init();
    });
    });
    }, "code-snippets");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "1"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53381995%2ffinding-adjacent-elements-in-a-2d-array-and-counting-them%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    1
    down vote













    In each iteration, you can use your i,j variables to "navigate" the 2d plane and see if any interacting items are the same. In each iteration you would check the following indexes to see if they are the same:




    • image[i-1][j] (one row up)

    • image[i+1][j] (one row down)

    • image[i][j-1] (one left)

    • image[i][j+1] (one right)


    Of course for all of these statements first you should check if +1/-1 is still within the size of your matrix, otherwise you will end up with out of bounds exception.






    share|improve this answer

























      up vote
      1
      down vote













      In each iteration, you can use your i,j variables to "navigate" the 2d plane and see if any interacting items are the same. In each iteration you would check the following indexes to see if they are the same:




      • image[i-1][j] (one row up)

      • image[i+1][j] (one row down)

      • image[i][j-1] (one left)

      • image[i][j+1] (one right)


      Of course for all of these statements first you should check if +1/-1 is still within the size of your matrix, otherwise you will end up with out of bounds exception.






      share|improve this answer























        up vote
        1
        down vote










        up vote
        1
        down vote









        In each iteration, you can use your i,j variables to "navigate" the 2d plane and see if any interacting items are the same. In each iteration you would check the following indexes to see if they are the same:




        • image[i-1][j] (one row up)

        • image[i+1][j] (one row down)

        • image[i][j-1] (one left)

        • image[i][j+1] (one right)


        Of course for all of these statements first you should check if +1/-1 is still within the size of your matrix, otherwise you will end up with out of bounds exception.






        share|improve this answer












        In each iteration, you can use your i,j variables to "navigate" the 2d plane and see if any interacting items are the same. In each iteration you would check the following indexes to see if they are the same:




        • image[i-1][j] (one row up)

        • image[i+1][j] (one row down)

        • image[i][j-1] (one left)

        • image[i][j+1] (one right)


        Of course for all of these statements first you should check if +1/-1 is still within the size of your matrix, otherwise you will end up with out of bounds exception.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 19 at 20:24









        peterxz

        104110




        104110






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Stack Overflow!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            To learn more, see our tips on writing great answers.





            Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


            Please pay close attention to the following guidance:


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53381995%2ffinding-adjacent-elements-in-a-2d-array-and-counting-them%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Costa Masnaga

            Fotorealismo

            Sidney Franklin