<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> Reverse Polish notation (RPN), also known as Polish postfix notation or simply postfix notation, is a mathematical notation in which operators follow their operands, in contrast to Polish notation (PN), in which operators precede their operands . It does not need any parentheses as long as each operator has a fixed number of operands . The description "Polish" refers to the nationality of logician Jan Łukasiewicz, who invented Polish notation in 1924 . </P> <P> The reverse Polish scheme was proposed in 1954 by Arthur Burks, Don Warren, and Jesse Wright and was independently reinvented by Friedrich L. Bauer and Edsger W. Dijkstra in the early 1960s to reduce computer memory access and utilize the stack to evaluate expressions . The algorithms and notation for this scheme were extended by Australian philosopher and computer scientist Charles L. Hamblin in the mid-1950s . </P>

Polish and reverse polish notation in data structure