Decimal To Fraction 小数转换成分数

以0.25为例, 0.25 * 100 = 25, 求25 和 100 的最大公约数gcd. 25/gcd 为分子. 100/gcd为分母.

//小数转分数
//0.3 -> 3/10, 0.25 -> 1/4
public class dicimalToFraction{
    public static void main(String [] args){
        double a = 0.3;
        double b = 0.25;
        System.out.println(dicimalToFraction(a));
        System.out.println(dicimalToFraction(b));
    }

    public static String dicimalToFraction(double num){
        int count = 0;
        int base = 10;
        while(num != Math.floor(num)){
            num *= base;
            count++;
        }

        base = (int)Math.pow(base,count);
        int nor = (int)num;
        int gcd = findGCD(nor, base);


        return String.valueOf(nor/gcd) + "/" + String.valueOf(base/gcd);
    }


    //求最大公约数
    private static int findGCD(int a, int b){
        if(a == 0){
            return b;
        }
        return findGCD(b%a, a);
    }

}

与Fraction to Recurring Decimal类似.