Adepero below

Sometimes it is better to use a data structure or another structure that allows us more speed, if we want to execute a certain type of algorithm.

It's interesting to know something more than just the array or the map.

They have an index that allows you to access a specific position and the value that it holds.

Even if they are not ordered, they can be removed from the data in an orderly way.

This allows for great speed, for example, when implementing a priority queue where we want each element that we insert, if we suddenly insert many elements with a priority, the first to be taken is the one with more or less priority, it depends on the type of mound.

They can be used to implement the undo process, like when we write in a text editor and press the CTRL+Z key.

Blocks 1 and 2 are equivalent to writing something, as we see in the image. Blocks 2 and 3 are the equivalent of deletion a letter.

The last action that would be taken would be the one that deleted the letter and put it back, and that would have a function that would do certain operations.

Acronyms are part of the patois of today's obviously exhausted youth. Actually saying all the words in "You Only Live Once", "Not Suitable For Work" or "Rolling On Floor Laughing" would apparently leave them spent, so they have cleverly shortened their speaking time by acronymising common terms because, like, YOLO.

Even these clever clogs can't keep up with the world champions of acronym production, however, the car companies.

Manufacturers like to stuff as many of these as they can into every car they build, from the exciting sounding ESP through EBD, DOHC, AEB, BLIS and plenty more, but there is one in particular that they spend millions trying to do without – NVH.

It stands for Noise, Vibration and Harshness, and is basically a measure of how much unpleasant aural and tactile feedback the car delivers as you drive.

It's pretty well known that, much like cholesterol levels, stab wounds and K-Pop "music", exposure to noise, vibration and harshness is best kept to a minimum.

Put simply, the noise is what you can hear, the vibration is what you can feel and the harshness is how much of an effect thumps, bumps, noise and vibration have on the cabin and its occupants.

Removing and isolating passengers from NVH is a field that's seen monumental advances over the past few decades. Originally the preserve of the most luxurious marques - and an acronym that was only even discussed by premium brands - NVH reduction is a global push, spurred on by consumers who want increasing insulation from the environment they're driving through. Perhaps to avoid the sound of other humans ROFLing.

Today, we even expect sporty convertibles to be NVH minimal.

This presents a quandary for engineers. Traditional sound and vibration-deadening material adds weight, which can spoil acceleration, handling and fuel economy, so they've had to come up with lighter and more effective methods than the traditional bit of tar paper.

In some cases, though, technology that offers a better drive can also offer a quieter ride. Unfortunately, it doesn't come cheaply.

Noise, vibration and harshness are caused by the car's mechanical and electrical systems, as well as the car's interaction with road surfaces and its passage through the air.

The main sources of NVH in a car are its engine, drivetrain and tyres, as well as the sound of airflow along its body.

While we love a good engine note or exhaust burble, undesirable mechanical sounds and vibrations can emanate from a car's oily bits, such as a howling radiator fan, a shuddering when idling at traffic lights or a harsh, wince-inducing thump from a pothole.

Tyres are a huge source of noise, due to vibrations created by their rotation, which then travel along suspension mounts and into the cabin.

Low-profile tyres, found on sportier cars, tend to transmit more vibration through the suspension because the tighter, stiffer rubber can't absorb as much. Wide tyres are more susceptible due to a larger contact patch, but the soft, wide tread patterns of off-road tyres are the worst offenders.

Airflow over the car's body causes quite a bit of noise, especially at higher speeds and in large cars with the aerodynamic properties of a shipping container. Any interruptions the air faces in its journey across the car – such as aerials, roof racks and door mirrors – are rewarded with howling, whipping or buzzing noises in the cabin.

Cancelling out NVH comes down to three basic principles – reducing it at the source, isolating it from the car's main structure and absorbing as much as possible before it enters the cabin.

The first – if not the easiest – way to reduce NVH is to curb the number and volume of the sounds, vibrations and shocks produced in the first place.

Aerodynamics, for instance, play a huge part in the amount of noise. As air flows over the car body, any disturbances in its path create vibrations of the air particles, which is how sound is transmitted.

The weirdly shaped headlights on the Nissan Leaf are a good example of aerodynamics at work. According to Nissan, the headlight covers are shaped to redirect airflow past the wing mirrors; without some subtle air bending, the wind noise over the mirror housing would be conspicuously audible over the golf cart hum of the electric motor.

Car makers strive to make precise and well-balanced engine and drivetrain components to curb vibration; similarly, tyre manufacturers vary compounds and tread patterns to reduce unwanted harshness.

The second and perhaps equally complex way to reduce NVH is to isolate the car's main structure from the source. Complex and expensive suspension tech such as independent, multi-link and hydro-pneumatic systems isolate the chassis and steering column from road surfaces, removing vibration and shocks.

To further isolate the sources of noise, engine, suspension and exhaust components are mounted on rubber and polyurethane bushes rather than solid metal; the softer compounds work against the transmission of vibrations.

The last resort in the war against NVH is also the most conventional: absorbing as much as possible. Mechanically speaking, this tends to refer to steering dampers, which absorb the worst of the shocks introduced by poor road surfaces.

In the cabin, passive sound absorption can extend from a smattering of rubber-like sound deadening material fixed to various points along the chassis, all the way up to foam-filled pillars and double-glazed windows.

Double-pane glass and sound insulation tends to be pretty heavy, so the extent of sound deadening usually relates to the car's price and purpose. Rolls-Royces, for instance, are built like recording studios.

As you see in the diagram (above), begin the capital W barely below the topline creating a small tail at the top left of the letter Then, coming slightly to the right, take your stroke down to the bottom line Bringing your stroke back up, slightly below the top line