#include<iostream>
#include<cstdlib>
using namespace std;//遞歸版本的加法實現
int Add(int a, int b)
{return b ? Add(a^b, (a&b)<<1) : a;/*if(b)return plus_rec(a^b, (a&b)<<1);elsereturn a;*/
}//該為迭代版本
int Add_iter(int a, int b)
{int ans;while(b){ans = a^b;b = (a&b)<<1;a = ans;}return ans;
}//求a的相反數：將各位取反加一
int negative(int a) //get -a
{return Add(~a, 1);
}int Minus(int a, int b)
{return Add(a, negative(b));
}//正數乘法
int Multi(int a, int b)
{int ans = 0;while(b){if(b&1)ans = Add(ans, a);a = a << 1;b = b >> 1;}return ans;
}//正數除法
int Divide(int a, int b)
{int coun = 0;while(a >= b){a = Minus(a, b);coun = Add(coun, 1);}return coun;
}//判斷是否是負數，0，正數
int isneg(int a)
{return a & 0x8000;
}
int iszero(int a)
{return !(a & 0xFFFF);
}
int ispos(int a)
{return (a&0xFFFF) && !(a&0x8000);
}//處理負數的乘法和除法
int My_Multi(int a, int b)
{if(iszero(a) || iszero(b))return 0;if(isneg(a)){if(isneg(b))return Multi(negative(a), negative(b));elsereturn negative(Multi(negative(a), b));}else if(isneg(b))return negative(Multi(a, negative(b)));elsereturn Multi(a, b);
}int My_Divide(int a, int b)
{if(iszero(b)){cout << "Error!" << endl;exit(1);}if(iszero(a))return 0;if(isneg(a)){if(isneg(b))return Divide(negative(a), negative(b));elsereturn negative(Divide(negative(a), b));}else if(isneg(b))return negative(Divide(a, negative(b)));elsereturn Divide(a, b);}int main(int argc, char **argv)
{int a = 5;int aa = -5;int b = 3;int bb = -3;int c = 15;cout << Add(a, b) << endl;cout << Add(a, bb) << endl;cout << Minus(a, b) << endl;cout << Minus(b, a) << endl;cout << Multi(a, b) << endl;cout << My_Multi(aa, b) << endl;cout << Divide(c, a) << endl;return 0;
}
