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











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2
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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.










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  • 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






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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












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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.






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    up vote
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    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












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        answered Nov 19 at 20:24









        peterxz

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