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48 lines
804 B
48 lines
804 B
'use strict' |
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var abs = Math.abs |
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var round = Math.round |
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function almostEq(a, b) { |
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return abs(a - b) <= 9.5367432e-7 |
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} |
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//最大公约数 Greatest Common Divisor |
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function GCD(a, b) { |
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if (almostEq(b, 0)) return a |
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return GCD(b, a % b) |
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} |
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function findPrecision(n) { |
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var e = 1 |
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while (!almostEq(round(n * e) / e, n)) { |
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e *= 10 |
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} |
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return e |
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} |
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function num2fraction(num) { |
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if (num === 0 || num === '0') return '0' |
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if (typeof num === 'string') { |
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num = parseFloat(num) |
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} |
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var precision = findPrecision(num) //精确度 |
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var number = num * precision |
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var gcd = abs(GCD(number, precision)) |
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//分子 |
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var numerator = number / gcd |
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//分母 |
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var denominator = precision / gcd |
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//分数 |
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return round(numerator) + '/' + round(denominator) |
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} |
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module.exports = num2fraction |
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