objective-c第七章课后练习2

题：改变第七章例子中print方法，增加bool参数，判断如果是YES则对分数进行约简

@interface Fraction : NSObject
{
    //int num,den;
    
}
@property int num,den;//定义属性

- (void) print:(BOOL) yesOrNo;//打印并判断是否约简分数
//- (void) setN: (int) n;//设置n的值
//- (void) setD: (int) d;//设置d的值
//- (int) n;//返回n的值
//- (int) d;//返回d的值
- (void) setN: (int) n andSetD: (int) d;//2个参数的方法分别设置n和d的值
- (double) convertToNum;
- (void) add: (Fraction *) f;//分数相加方法
- (void) reduce;//分数约简方法
- (Fraction *) addFraction: (Fraction *) f;//加
- (Fraction *) subFraction: (Fraction *) f;//减
- (Fraction *) mulFraction: (Fraction *) f;//乘
- (Fraction *) divFraction: (Fraction *) f;//除
@end

#import "Fraction.h"

@implementation Fraction

@synthesize num,den;//属性对应@property num,den

- (void) print: (BOOL) yesOrNo//打印
{
    if (yesOrNo == YES) {
        [self reduce];
    }
    NSLog(@"%i/%i",num,den);
}
//- (void) setN: (int) n//设置n的值
//{
//    num = n;
//}
//- (void) setD: (int) d//设置d的值
//{
//    den = d;
//}
//- (int) n//返回n的值
//{
//    return num;
//}
//- (int) d//返回d的值
//{
//    return den;
//}

- (void) setN: (int) n andSetD: (int) d
{
    num = n;
    den = d;
    
}
- (double) convertToNum
{
    if (den != 0)
    {
        return (double) num/den;
    
    }
    else
    {
        return NAN;
        
    }
}

- (void) add: (Fraction *) f
{
    //分数相加:a/b + c/d = ((a*d) + (b*c)) / (b*d)
    
    num = num * f.den + den * f.num;
    den = den * f.den;
    
    [self reduce];
}

- (void) reduce
{
    int u = num;
    int v = den;
    int temp;
    
    while (v != 0)
    {
        temp = u % v;
        u = v;
        v = temp;
        
    }
    num /= u;
    den /= u;
}

//加法
- (Fraction *) addFraction: (Fraction *) f
{
    Fraction *result = [[Fraction alloc]init];
    
    result.num = num * f.den + den * f.num;
    
    result.den = den * f.den;

    [result reduce];
    
    return result;
    
}

//减法
- (Fraction *) subFraction: (Fraction *) f
{
    Fraction *result = [[Fraction alloc]init];
    
    result.num = num * f.den - den * f.num;
    result.den = den * f.den;
    
    [result reduce];
    
    return result;
    
}

//乘法
- (Fraction *) mulFraction: (Fraction *) f
{
    Fraction *result = [[Fraction alloc]init];
    
    result.num = num * f.num;
    result.den = den * f.den;
    
    [result reduce];
    
    return result;
}

//除法
- (Fraction *) divFraction: (Fraction *) f
{
    //计算分数除以分数，第一个分数乘以第二个分数的倒数：1/2除以3/2 = 1/2 * 2/3
    Fraction *result = [[Fraction alloc]init];
    
    result.num = num * f.den;
    result.den = den * f.num;
    
    //[result reduce];
    
    return result;
}
@end

#import <Foundation/Foundation.h>
#import "Fraction.h"

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        Fraction *myF = [[Fraction alloc]init];
        Fraction *myF_2 = [[Fraction alloc]init];
        Fraction *myResult;
        
        
        [myF setN:1 andSetD:2];
        [myF_2 setN:3 andSetD:2];
        
        myResult = [myF subFraction:myF_2];
        //[myResult print];
        
        myResult = [myF mulFraction:myF_2];
        //[myResult print];
        
        myResult = [myF divFraction:myF_2];
        
        int i;//定义整型变量i记录输入值
        BOOL b;//定义BOOL类型通过i值传递判断yes or no
        NSLog(@"Need to Simple? 1 or 0");
        //NSLog(@"ifReadOnly value: %@" ,ifReadOnly?@"YES":@"NO");
        scanf("%i",&i);
        b = i;//将i值赋给b
        [myResult print:b];
        
        
        
    }
    return 0;
}