- published: 12 Jan 2015
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In computer science, A* (pronounced as "A star" ( listen)) is a computer algorithm that is widely used in pathfinding and graph traversal, the process of plotting an efficiently traversable path between multiple points, called nodes. Noted for its performance and accuracy, it enjoys widespread use. However, in practical travel-routing systems, it is generally outperformed by algorithms which can pre-process the graph to attain better performance, although other work has found A* to be superior to other approaches.
Peter Hart, Nils Nilsson and Bertram Raphael of Stanford Research Institute (now SRI International) first described the algorithm in 1968. It is an extension of Edsger Dijkstra's 1959 algorithm. A* achieves better performance by using heuristics to guide its search.
In 1968, AI researcher Nils Nilsson was trying to improve the path planning done by Shakey the Robot, a prototype robot that could navigate through a room containing obstacles. This path-finding algorithm, that Nilsson called A1, was a faster version of the then best known method, Dijkstra's algorithm, for finding shortest paths in graphs. Bertram Raphael suggested some significant improvements upon this algorithm, calling the revised version A2. Then Peter E. Hart introduced an argument that established A2, with only minor changes, to be the best possible algorithm for finding shortest paths. Hart, Nilsson and Raphael then jointly developed a proof that the revised A2 algorithm was optimal for finding shortest paths under certain well-defined conditions.
Patrick Chukwuemeka Okogwu (born 7 November 1988), better known by his stage name Tinie Tempah, is an English rapper, singer, songwriter, and record producer. He has been signed to Parlophone Records since 2009, a subsidiary of Warner Music Group. He created his own record and fashion label Disturbing London (DL Records) in 2007 along with his cousin, Dumi Oburota.
After releasing a couple of mixtapes, he released his long-awaited debut album, Disc-Overy, in October 2010. Preceded by two British number-one singles; "Pass Out" and "Written in the Stars", the album charted at number one and was certified Platinum the next year. In February 2011, he won two Brit Awards for Best British Breakthrough Act and Best British Single.
In November 2013, he released his second album, entitled Demonstration. Preceded by top ten singles "Trampoline" and "Children of the Sun", the album charted at number three and was certified gold by the BPI the next year. In June 2015, he released the first single from his upcoming third album, entitled "Not Letting Go". This gave Tempah his sixth UK number one, the most by any rap artist. However, on the week of 23 October 2015, Tempah earned his seventh UK number one single with "Turn the Music Louder (Rumble)", a song by KDA, which also features English singer-songwriter Katy B.
There was a girl who couldn't speak
Who couldn't speak her mind
Only thing she was good at
Was telling stories of faraway lands
There was a guy who couldn't say
Who couldn't say what he wanted
Only thing he was good at
Was cracking jokes to make people laugh
So many words he swallowed
So many thoughts she kept to herself
And when they met they made love
And talked about the world and the weather
So many cities he walked
So many countries she traveled
And in their dreams they would listen