32 lines
933 B
JavaScript
32 lines
933 B
JavaScript
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const fs = require('fs');
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const expressions = fs.readFileSync('./input.txt', 'utf-8').split('\n');
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function calc (expression) {
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// if it's just a number, do nothing
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if (!isNaN(Number(expression))) { Number(expression) }
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// if there's brackets, do that first
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while (expression.match(/\(/)){
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expression = expression.replace(/\([^()]+\)/, match =>
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calc (match.slice(1, match.length-1))
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)
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}
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// if there's addition, do that
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while (expression.match(/\+/)){
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expression = expression.replace(/(\d+) \+ (\d+)/, (match, a, b) =>
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parseInt(a) + parseInt(b)
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)
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}
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// if there's multiplication, do that
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while (expression.match(/\*/)) {
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expression = expression.replace(/(\d+) \* (\d+)/, (match, a, b) =>
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parseInt(a) * parseInt(b)
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)
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}
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return Number(expression)
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}
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let runningTotal = 0
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for (expression of expressions) {
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runningTotal += calc (expression)
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}
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console.log(runningTotal)
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