/*最大公约数*/ int gcd(int a,int b){ if(b == 0) return a; return gcd(b,a%b); } /*最小公倍数*/ cout< 递归+出口 #include #include #include using namespace std; /*最大公约数*/ int gcd(int a,int b){ if(b == 0) return a; return gcd(b,a%b); } struct Fraction{ int up,down; }; /*分数的化简*/ Fraction fun(Fraction result){ if(result.down<0){ result.down = -result.down; result.up = -result.up; } if(result.up == 0){ result.down = 1; }else{ int d = gcd(abs(result.up),abs(result.down)); result.up /=d; result.down /=d; } return result; } /*分数的加法*/ Fraction add(Fraction x1,Fraction x2){ Fraction result; x1 = fun(x1); x2 = fun(x2); result.up = x1.up*x2.down+x1.down*x2.up; result.down = x1.down*x2.down; return fun(result); } int main(){ Fraction result,x1,x2; while(cin>>x1.up>>x1.down>>x2.up>>x2.down){ result = add(x1,x2); /*分数的输出*/ if(result.down == 1){ cout<