如何将小数转换为分数？

Question

我需要将十进制转换为分数.它很容易转换为10英尺.

1.5 => 15/10

这可以通过以下代码完成:

public class Rational {

    private int num, denom;

    public Rational(double d) {
        String s = String.valueOf(d);
        int digitsDec = s.length() - 1 - s.indexOf('.');
        int denom = 1;
        for (int i = 0; i < digitsDec; i++) {
            d *= 10;    
            denom *= 10;
        }

        int num = (int) Math.round(d);
        this.num = num;
        this.denom = denom;
    }

    public Rational(int num, int denom) {
        this.num = num;
        this.denom = denom;
    }

    public String toString() {
        return String.valueOf(num) + "/" + String.valueOf(denom);
    }

    public static void main(String[] args) {
        System.out.println(new Rational(1.5));
    }
}

但我想要的是

1.5 => 3/2

我不知道如何继续 我的问题不是重复.因为其他相关问题是C#.这是java.

Answer 1

你应该找到结果数的最大公约数,并用它除以分子和分母.

这是一种方法:

public class Rational {

    private int num, denom;

    public Rational(double d) {
        String s = String.valueOf(d);
        int digitsDec = s.length() - 1 - s.indexOf('.');
        int denom = 1;
        for (int i = 0; i < digitsDec; i++) {
            d *= 10;    
            denom *= 10;
        }

        int num = (int) Math.round(d);
        int g = gcd(num, denom);
        this.num = num / g;
        this.denom = denom /g;
    }

    public Rational(int num, int denom) {
        this.num = num;
        this.denom = denom;
    }

    public String toString() {
        return String.valueOf(num) + "/" + String.valueOf(denom);
    }

    public static int gcd(int num, int denom) {
          ....
    }

    public static void main(String[] args) {
        System.out.println(new Rational(1.5));
    }
}

Answer 2

static private String convertDecimalToFraction(double x){
    if (x < 0){
        return "-" + convertDecimalToFraction(-x);
    }
    double tolerance = 1.0E-6;
    double h1=1; double h2=0;
    double k1=0; double k2=1;
    double b = x;
    do {
        double a = Math.floor(b);
        double aux = h1; h1 = a*h1+h2; h2 = aux;
        aux = k1; k1 = a*k1+k2; k2 = aux;
        b = 1/(b-a);
    } while (Math.abs(x-h1/k1) > x*tolerance);

    return h1+"/"+k1;
}

我从这里得到了这个答案.我所要做的就是将他的答案转换为java.