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programming exercise RPN calculator

some of the best calculators in the world have an 'RPN' (reverse polish notation) mode. we would like you to write a command-line based RPN calculator.

requirements

• the calculator has a stack that can contain real numbers.
• the calculator waits for user input and expects to receive strings containing whiitespace separated lists of numbers and operators
• numbers are pushed on to the stack. operators operate on numbers that are on the stack
• availavble operators are +,-,*,/,sqrt,undo,clear
• the 'clear' operator removes all items from the stack.
• the 'undo' operator undoes the previous operation. 'undo undo' will unfo the previous two operations.
• sqrt performs a square root on the top item from the stack.
• The '+', '-', '*', '/' operators perform addotion, subtraction, multipliplication and division respectively on the top two items from the stack.
• after processing an input string, the calculator displays the contents of the stack as a space-asparate list.
• numbers should be stored on the stack to at least 15 decimal places of precision, but displayed to 10 decimal places (or less if cause no loss of precision).
• all numbers should be formatted as plain decimal strings (ie, no engineering formatting).
• if an operator cannot find a sufficient number of parameters on the stack, a warning is displayed: operator (position: ): insufficient parameters.
• after displaying the warning. all further processing of the string terminates and the current state of the stack is displayed

deliverables

• the solution submitted should indude structure,source code, configuration and any tests or test code you deem necessary - no need to package class files.
• the solution submitted should use idea as possable as you can.
• solve the problem in java, C# or in a specific language that you may have been directed to use.
• solve the problem as though it were "production level" code.
• it is not required to provide any graphical inter face.
• push code to github and send adress to email when you finished coding.
• in order to get around firewall issues we recommend the solution be packaged as a password protected zip file.

examples

examples 1

5 2
stack: 5 2

examples 2

2 sqrt
stack: 1.4142135623
clear 9 sqrt
stack: 3

example 3

5 2 -
stack: 3
3 -
stack: 0
clear
stack:

example 4

5 4 3 2
stack: 5 4 3 2
undo undo *
stack: 20
5 *
stack: 100
undo
stack: 20 5

example 5

7 12 2 /
stack: 7 6
*
stack: 42
4 /
stack: 10.5

example 6

1 2 3 4 5
stack: 1 2 3 4 5
*
stack: 1 2 3 20
clear 3 4 -
stack: -1

example 7

1 2 3 4 5
stack: 1 2 3 4 5
* * * *
stack: 120

example 8

1 2 3 * 5 + * * 6 5
operator * (opsition: 15): insufficlent parameters stack: 11
(the 6 and 5 were not pushed on to the stack due to the previous error)