Java 有理数类——分数和整数

public class 有理数 {

	public static void main(String[] args) {
		Rational a = new Rational(1, 3);
		Rational b = new Rational(1, 6);
		Rational c = a.add(b);
		String result = c.toString();
		System.out.println(a + " + " + b + " = " + result);
	}
	
	//内部类
	static class Rational {

		private long ra;
		private long rb;

		// 求最小公约数
		public long gcd(long a, long b) {
			if (b == 0) {
				return a;
			} else {
				return gcd(b, a % b);
			}
		}

		// 构造函数
		public Rational(long a, long b) {
			ra = a;
			rb = b;
			long k = gcd(ra, rb);// 求公约数

			if (k > 1) {// 进行约分
				ra /= k;
				rb /= k;
			}
		}

		// 加法
		public Rational add(Rational x) {

			return new Rational(x.ra * this.rb + this.ra * x.rb, x.rb * this.rb);
		}

		// 乘法
		public Rational mul(Rational x) {
			// 当前对象分子*x的分子 ；当前对象分母*x的分母
			return new Rational(ra * x.ra, rb * x.rb);
		}

		public String toString() {
			if (rb == 1) {
				return "" + ra;
			} else {
				return ra + "/" + rb;
			}
		}

	}
}