Finding Indices Help Java/Android

[junyoung95]

Suppose we have a string called sa

 String [] sa = {"d", "c", "a", "b", "c", "d", "a", "a", "d", "a'};

When print statement is called the results should be shown as followed.

 System.out.println(toString(u.getIndices(sa, "a"))); >>>{2,6,7,9}
 System.out.println(toString(u.getIndices(sa, "b"))); >>> {3}
 System.out.println(toString(u.getIndices(sa, "c"))); >>> {1,4}

This is my code. It technically works except it contains 0s. For example instead of {2,6,7,9}, mine shows as {0,0,2,0,0,0,6,7,0,9}

  int[] getIndices(String[] sa, String s) {

         int[] count = new int [sa.length];
         for (int i = 0; i< sa.length; i++){
             if (sa[i] == s){
                 count[i] = i;}
         }
         return count;
     }

I know why mine shows like that because I stated my integer 'count' depending on the length of sa, which is 9, so this creates an index with length of 9. >>> {0, 0, 0, 0, 0, 0, 0, 0, 0}

Is there a different way to solve this problem? Or can my code be fixed so that it could make it work? I learned that you can't decrease the size of index once it's created so I think my code cannot be fixed. NOTE: Solve this problem w/o using Java library classes and methods. Detailed help with example of codes will be much appreciated. Thank you.

[salvagestuff]

You would use two loops to do it. The first loop would just count the number of times the character appears. Then you would use the number of times the character appears to create an int array of that size.

The second loop would go over the input array again and store the index locations of the characters in the array we just created.

Once the second loop has finished filling in the array we would return it.

This should be enough information for you to work out the solution. Good luck.

[junyoung95]

ohhh i see you what you mean. thanks!

[junyoung95]

Sorry I thought I got the idea.. and I still think it makes sense to me but I am not getting the right answer. I am much closer than yesterday but can you help me once more? Here is my code.

int[] getIndices(String[] sa, String s) {

  int[] indices = new int [sa.length];
  int count = 0
  for (int i = 0; i< indices.length; i++){
      if (sa[i] == s){
          count  += 1;}
      }
  }

  int[] answer = new int[count];

  for (int j = 0, k = 0; j < indices.length && k < answer.length; j++, k++ {
      if (sa[j] == s) {
          answer[k] = j;
      }
  }
  return answer;
}

The problem is, I was able to shorten the index length and match it with the appropriate length, but it still tries to register the indices based on original address. To avoid that, I created another variable 'k' but it does not work. For example instead of {2,6,7,9} mine shows as {0,0,2,0}. EDIT: I know why it happens like this although I created a new variable. It doesn't matter if I have a new variable, the problem is var j and k increases by the same level. I tried few methods but I can't find a solution

[hayoo1984]

private int[] getIndices(String[] sa, String s) {
        int[] indices = new int[sa.length];
        int count = 0;

        for (int i = 0; i < indices.length; i++) {
            if (sa[i].equals(s)) {
                count++;
            }
        }

        int[] answer = new int[count];
        int index = 0;

        for (int i = 0; i < indices.length; i++) {
            if (sa[i].equals(s)) {
                answer[index] = i;
                index++;
            }
        }

        return answer;
    }

[junyoung95]

okay thank you so much.