49 lines
804 B
JavaScript
49 lines
804 B
JavaScript
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'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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