java sudoku solver

for (int row = 0; row < SIZE; row++) {
         for (int col = 0; col < SIZE; col++) {
          // we search an empty cell
          if (board[row][col] == EMPTY) {
            // we try possible numbers
            for (int number = 1; number <= SIZE; number++) {
              if (isOk(row, col, number)) {
                // number ok. it respects sudoku constraints
                board[row][col] = number;

                if (solve()) { // we start backtracking recursively
                  return true;
                } else { // if not a solution, we empty the cell and we continue
                  board[row][col] = EMPTY;
                }
             }
            }

            return false; // we return false
           }
          }
         }

         return true; // sudoku solved