好的，先弄出个类来，代码如下:
View Code 1 class fraction 2 { 3 private: 4 int numerator; //分子 5 int denominator; //分母 6 public: 7 fraction(int x = 0, int y = 1); 8 ~fraction(); 9 10 const fraction add(const fraction w);11 const fraction add(int k); // " + "12 13 const fraction sub(const fraction w); // " - "14 const fraction sub(int k);15 16 const fraction mul(const fraction w); // " * "17 const fraction mul(int k);18 19 const fraction div(const fraction w); // " / "20 const fraction div(int k);21 22 int commonden(void);23 void show(void);24 25 //增加的成员函数26 void setn(int x); //设定分子27 void setd(int y); //设定分母28 int getn(void)const;29 int getd(void)const;30 };
各成员实现如下：
View Code 1 // 构造函数 2 fraction::fraction( int x, int y) 3 { 4 numerator = x; 5 if (y == 0 ) 6 { 7 cout << " 分母为0 " << endl; 8 exit( 0 ); 9 } 10 denominator = y; 11 } 12 13 fraction:: ~ fraction() 14 { 15 // 虚构函数 16 } 17 // 加法 18 const fraction fraction::add( const fraction w) 19 { 20 fraction z; 21 z.numerator = numerator * w.denominator + w.numerator * denominator; 22 z.denominator = denominator * w.numerator; 23 return z; 24 } 25 26 // 成员函数的重载 27 // 分数 + 整数 28 const fraction fraction::add( int k) 29 { 30 fraction z; 31 z.numerator = numerator + k * denominator; 32 z.denominator = denominator; 33 return z; 34 } 35 36 // 减法 37 const fraction fraction::sub( const fraction w) 38 { 39 fraction z; 40 z.numerator = numerator * w.denominator - w.numerator * denominator; 41 z.denominator = denominator * w.numerator; 42 return z; 43 } 44 45 // 成员函数的重载 46 // 分数 - 整数 47 const fraction fraction::sub( int k) 48 { 49 fraction z; 50 z.numerator = numerator - k * denominator; 51 z.denominator = denominator; 52 return z; 53 } 54 55 // 乘法 56 const fraction fraction::mul( const fraction w) 57 { 58 fraction z; 59 z.numerator = numerator * w.numerator; 60 z.denominator = denominator * w.denominator; 61 return z; 62 } 63 64 // 成员函数的重载 65 // 分数 * 整数 66 const fraction fraction::mul( int k) 67 { 68 fraction z; 69 z.numerator = k * numerator; 70 z.denominator = denominator; 71 return z; 72 } 73 74 // 除法 75 const fraction fraction::div( const fraction w) 76 { 77 fraction z; 78 if (numerator == 0 || w.numerator == 0 ) 79 { 80 cout << " 两个分子为零的分数相除没有意义 " << endl; 81 exit( 0 ); 82 } 83 z.numerator = numerator * w.denominator; 84 z.denominator = denominator * w.numerator; 85 return z; 86 } 87 88 // 成员函数的重载 89 // 分数 / 整数 90 const fraction fraction::div( int k) 91 { 92 fraction z; 93 if (numerator == 0 || k == 0 ) 94 { 95 cout << " 两个分子为零的分数相除没有意义 " << endl; 96 exit( 0 ); 97 } 98 z.numerator = numerator; 99 z.denominator = k * denominator; 100 return z; 101 } 102 103 // 函数功能：使输出的分数为真分数 104 int fraction::commonden( void ) 105 { 106 int m,n,p; 107 m = denominator; 108 n = numerator; 109 do 110 { 111 p = m % n; 112 m = n; 113 n = p; 114 } while (p != 0 ); 115 return m; 116 } 117 118 void fraction::show( void ) 119 { 120 if (numerator == 0 ) 121 { 122 cout << " = 0 " << endl; 123 } 124 else 125 { 126 if (numerator == denominator) 127 { 128 cout << " = 1 " << endl; 129 } 130 else 131 { 132 cout << " = " << numerator / commonden() << " / " << denominator / commonden() << endl; 133 } 134 } 135 } 136 137 void fraction::setn( int x) // 设定分子 138 { 139 numerator = x; 140 } 141 void fraction::setd( int y) // 设定分母 142 { 143 denominator = y; 144 } 145 int fraction::getn( void ) const 146 { 147 return numerator; 148 } 149 int fraction::getd( void ) const 150 { 151 return denominator; 152 }
好了，写个主函数来测试下
View Code void main(){ fraction w(6,7),t(9,5),d; cout << "(6/7) + (9/5)"; d = w.add(t); d.show(); cout <<endl; cout << "(6/7) + 1"; // 6 13 d = w.add(1); // - + 1 = - d.show(); // 7 7 cout <<endl; cout << "(6/7) - (9/5)"; d = w.sub(t); d.show(); cout <<endl; cout << "(6/7) - 1"; d = w.sub(1); d.show(); cout <<endl; cout << "(6/7) * (9/5)"; d = w.mul(t); d.show(); cout <<endl; cout << "(6/7) * 2"; d = w.mul(2); d.show(); cout <<endl; cout << "(6/7) / (9/5)"; d = w.div(t); d.show(); cout <<endl; cout << "(6/7) / 2"; d = w.div(2); d.show(); cout <<endl; return ;}
来看看测试结果吧！