分数（有理数）的四则运算PAT1088

2015-02-05

PAT- B1088. Rational Arithmetic (20)

http://www.patest.cn/contests/pat-a-practise/1088

 #include <iostream>
 #include <cmath>
 using namespace std;
 typedef long long LL;
 typedef struct Fraction{
     LL up,down;
 };
 LL gcd(LL a,LL b){
     return b== ? a : gcd(b,a%b);
 }
 Fraction reduction(Fraction res){
     if(res.down<){
         res.down=-res.down;
         res.up=-res.up;
     }
     else if(res.up==)
         res.down==;
     else{
         LL d=gcd(abs(res.up),res.down);
         res.up/=d;
         res.down/=d;
     }
     return res;
 }
 Fraction add(Fraction a,Fraction b){
     Fraction res;
     res.up=a.up*b.down+a.down*b.up;
     res.down=a.down*b.down;
     return reduction(res);
 }
 Fraction sub(Fraction a,Fraction b){
     Fraction res;
     res.up=a.up*b.down-a.down*b.up;
     res.down=a.down*b.down;
     return reduction(res);
 }
 Fraction multi(Fraction a,Fraction b){
     Fraction res;
     res.up=a.up*b.up;
     res.down=a.down*b.down;
     return reduction(res);
 }
 Fraction divide(Fraction a,Fraction b){
     Fraction res;
     res.up=a.up*b.down;
     res.down=a.down*b.up;
     return reduction(res);
 }
 void showFraction(Fraction res){
     res=reduction(res);
     if(res.up<)
         printf("(");
     if(res.down==)
         printf("%lld",res.up);
     else if(res.up==)
         printf("");
     else if(abs(res.up)>res.down){
         printf("%lld %lld/%lld",res.up/res.down,abs(res.up)%res.down,res.down);
     }
     else{
         printf("%lld/%lld",res.up,res.down);
     }
     if(res.up<)
         printf(")");
 }
 void output(Fraction a,Fraction b,char ch){
     showFraction(a);
     printf(" %c ",ch);
     showFraction(b);
     printf(" = ");
     switch(ch){
         case '+':
             showFraction(add(a,b));
             break;
         case '-':
             showFraction(sub(a,b));
             break;
         case '*':
             showFraction(multi(a,b));
             break;
         case '/':
             if(b.up==)
                 printf("Inf");
             else
                 showFraction(divide(a,b));
             break;
         default:
             printf("error");
             break;
     }
     printf("\n");
 }
 int main()
 {
     Fraction a,b,ans;
     while(scanf("%lld/%lld %lld/%lld",&a.up,&a.down,&b.up,&b.down)!=EOF){
         a=reduction(a);
         b=reduction(b);
         output(a,b,'+');
         output(a,b,'-');
         output(a,b,'*');
         output(a,b,'/');
     }
     return ;
 }