33 lines
1.1 KiB
Markdown
33 lines
1.1 KiB
Markdown
### infixToPostfix
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(WARNING)! :- Does not handles `unary` operator
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```js
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const infixToPostfix = expr => {
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let rpn = ''
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let solve = expr.replace(/\^/g,'**')str.replace(/([^\d])\.(\d+)/g, '$10.$2').match(/((\d\.?)+|[\+\(\)\/\-]|\*+)/g).filter(el => !/\s+/.test(el) && el !== '')
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let stack = []
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let precedence = {'**':5,'/':4,'*':4,'+':3,'-':3}
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solve.forEach(symbol => {
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if(!isNaN(parseFloat(symbol)) && isFinite(symbol)){
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rpn += symbol + ' '
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}
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else if (Object.keys(precedence).includes(symbol)) {
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while(((precedence[symbol] < precedence[stack[stack.length-1]]) || ((precedence[symbol] == precedence[stack[stack.length-1]]) && symbol !== "**"))&&(stack[stack.length - 1] !== '(')) {
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rpn += stack.pop() + ' '
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}
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stack.push(symbol)
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}
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else if(symbol === '('){stack.push(symbol)}
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else if(symbol === ')'){while (stack[stack.length - 1] !== '('){rpn += stack.pop() + ' '; if (stack.length === 0){throw `Mismatched parantheses`}} stack.pop()}
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else {throw `${symbol} is not a recognized symbol`}
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})
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while(stack.length !== 0){
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rpn += stack.pop() + ' '
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}
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return rpn
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}
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```
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```js
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```
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