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e112434dee
* Add prettier config * test: add test to check for absolute function * chore: es5 to es6 * test: add test to check mean function * test: add test for sum of digit * test: add test for factorial * test: add test for fibonnaci * test: add test for find HCF * test: add test for lcm * test: add gridget test * test: add test for mean square error * test: add test for modular binary exponentiation * test: add tests for palindrome * test: add test for pascals triangle * test: add tests for polynomial * test: add tests for prime check * test: add tests for reverse polish notation * test: add tests for sieve of eratosthenes * test: add tests for pi estimation monte carlo method * chore: move tests to test folder * chore: fix standardjs errors
34 lines
627 B
JavaScript
34 lines
627 B
JavaScript
// Wikipedia: https://en.wikipedia.org/wiki/Reverse_Polish_notation
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const calcRPN = (expression) => {
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const operators = {
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'+': (a, b) => a + b,
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'-': (a, b) => a - b,
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'*': (a, b) => a * b,
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'/': (a, b) => b / a
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}
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const tokens = expression.split(' ')
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const stack = []
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tokens.forEach((token) => {
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const operator = operators[token]
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if (typeof operator === 'function') {
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const a = stack.pop()
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const b = stack.pop()
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const result = operator(a, b)
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stack.push(result)
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} else {
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stack.push(parseFloat(token))
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}
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})
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return stack.pop()
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}
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export { calcRPN }
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