Diagonal Difference Hackerrank Solution - java for explanation watch video : Code: import java.io.*; import java.math.*; import java.security.*; import java.text.*; import java.util.*; import java.util.concurrent.*; import java.util.function.*; import java.util.regex.*; import java.util.stream.*; import static java.util.stream.Collectors.joining; import static java.util.stream.Collectors.toList; class Result { /* * Complete the 'diagonalDifference' function below. * * The function is expected to return an INTEGER. * The function accepts 2D_INTEGER_ARRAY arr as parameter. */ public static ...