分数的四则运算

实现分数的加减乘除运算

@implementation Fraction

- (void)setNumerator:(NSInteger)numerator{

    _numerator = numerator;

}

- (NSInteger)numerator{

    return _numerator;

}

- (void)setDenominator:(NSInteger)denominator{

    _denominator = denominator;

}

- (NSInteger)denominator{

    return _denominator;

}

-(instancetype)initWithNumerator:(NSInteger)numerator denominator:(NSInteger)denominator{

    self = [super init];

    if (self) {

        _numerator = numerator;

        _denominator = denominator;

     }

    return self;

}

+ (Fraction *)NumeratorWithNumerator:(NSInteger)numerator denominator:(NSInteger)denominator{

    return [[Fraction alloc] initWithNumerator:numerator denominator:denominator];

}

//一个方法如果不在.h中声明,外部使用对象的时候无法调用,这个方法就只能在这个类的内部使用

//求最大公约数

- (NSInteger)gcdWithNum1:(NSInteger)num1 num2:(NSInteger)num2{

    //辗转相除法

    while (num2 != 0) {

        NSInteger temp = num2;

        num2 = num1 % num2;

        num1 = temp;

    }

    return num1;

}

//输出分数

- (void)print{

    if (_numerator == _denominator && _numerator != 0 && _denominator != 0) {

        NSLog(@"1");

    }else if (_numerator == 0 && _denominator != 0){

        NSLog(@"0");

    }else if (_denominator == 0){

        NSLog(@"分母不能为0");

    }else if (_denominator < 0){

        NSLog(@"%ld %ld", -_numerator, -_denominator);

    }else{

        NSLog(@"%ld %ld", _numerator, _denominator);

    }

}

//约分

- (void)reduce{

   //计算最大公约数

    NSInteger gcd = [self gcdWithNum1:_numerator num2:_denominator];

    _numerator /= gcd;

    _denominator /= gcd;

    NSLog(@"%ld %ld", _numerator, _denominator);

}

//加法

- (Fraction *)addFraction:(Fraction *)anotherFraction{

   //加过之后的分子

    NSInteger newNum = self.numerator * anotherFraction.denominator + self.denominator * anotherFraction.numerator;

   //加过之后的分母

    NSInteger newDenom = self.denominator * anotherFraction.denominator;

    Fraction *result = [[Fraction alloc] initWithNumerator:newNum denominator:newDenom];

    return result;

}

//减

- (Fraction *)subtractFraction:(Fraction *)anotherFraction{

    NSInteger newNum = self.numerator * anotherFraction.denominator - self.denominator * anotherFraction.numerator;

    NSInteger newDenom = self.numerator * anotherFraction.denominator;

    Fraction *result = [[Fraction alloc] initWithNumerator:newNum denominator:newDenom];

    return result;

}

//乘

- (Fraction *)multiplyFraction:(Fraction *)anotherFraction{

    NSInteger newNum = self.numerator * anotherFraction.numerator;

    NSInteger newDonm = self.denominator * anotherFraction.denominator;

    Fraction *result = [[Fraction alloc] initWithNumerator:newNum denominator:newDonm];

    return result;

}

//除

- (Fraction *)divideFraction:(Fraction *)anotherFraction{

    NSInteger newNum = self.numerator * anotherFraction.denominator;

    NSInteger newDonm = self.denominator * anotherFraction.numerator;

    Fraction *result = [[Fraction alloc] initWithNumerator:newNum denominator:newDonm];

    return result;

}