Good kata!

Most of the sample tests are incorrect.

assertArrayEquals(new String[][]{
          {"2", "+", "3", "=", "5"},
          {"+", " ", "+", " ", "+"},
          {"4", "+", "1", "=", "5"},
          {"+", " ", "+", " ", "+"},
          {"6", "+", "2", "=", "8"} // 5 + 5 != 8, the symbols in the fourth row should = instead of +.
      }, CrossMath.solve(new String[][]{
          {"2", "+", "3", "=", "C"},
          {"+", " ", "+", " ", "+"},
          {"A", "+", "1", "=", "5"},
          {"+", " ", "+", " ", "+"},
          {"6", "+", "B", "=", "8"}
      }));

assertArrayEquals(new String[][]{
          {"1", "+", "3", "=", "4"},
          {"+", " ", "-", " ", "+"},
          {"3", "-", "3", "=", "0"},
          {"=", " ", "=", " ", "="},
          {"4", "+", "0", "=", "8"} // 4 + 0 != 8.
      }, CrossMath.solve(new String[][]{
          {"1", "+", "3", "=", "4"},
          {"+", " ", "-", " ", "+"},
          {"A", "-", "3", "=", "0"},
          {"=", " ", "=", " ", "="},
          {"B", "+", "C", "=", "8"}
      }));

assertArrayEquals(new String[][]{
          {"48", "/", "2", "=", "24"},
          {"/",  " ", "/",  " ", "/"},
          {"24", "/", "2", "=", "12"},
          {"=",  " ", "=",  " ", "="},
          {"12", "/", "2", "=", "6"} // 48 / 24 != 12; 2 / 2 != 2; 24 / 12 != 6.
      }, CrossMath.solve(new String[][]{
          {"48", "/", "C", "=", "24"},
          {"/",  " ", "/",  " ", "/"},
          {"24", "/", "B", "=", "12"},
          {"=",  " ", "=",  " ", "="},
          {"A", "/", "2", "=", "6"}
      }));

(Spoiler: unicode shenanigans)

What if input already has asterisks in it?

#barba

this kata needs feedback https://www.codewars.com/kata/6809ffd5fcdb184cdb7592b6/java

It's been resolved. I've updated the type hint to str | None to correctly reflect that None is a valid input.
Thanks for the feedback!

Type hints do not match the input types in Python.

Since None is a valid input, the annotations should be the following

def octopus(idea: str | None) -> str:

It's quite similar, but works in a different way.
Anyway, thanks for pointing it out!

This kata needs feedback CrossMath

New traduction for revision Traduction

Issue resolved, thanks for the feedback!

I think this has been done before (myjinxin kata about 'my daughter's school homework', or something like that)

src/main/java/CrossMath.java:4: error: cannot find symbol
    return String[0][0];

initial solution set-up needs new keyword

Sorry, I forgot to change Python and Kotlin tests. Now it should be ok.