@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 != )

     {

         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 != )

     {

         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: andSetD:];

         [myF_2 setN: andSetD:];

         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 ;

 }