PAT甲题题解-1088. Rational Arithmetic (20)-模拟分数计算

输入为两个分数，让你计算+,-,*,\四种结果，并且输出对应的式子，分数要按带分数的格式k a/b输出
如果为负数，则带分数两边要有括号
如果除数为0，则式子中的结果输出Inf
模拟题最好自己动手实现，考验细节处理，其它没啥好说的。

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>

using namespace std;
long long numerator[];
long long denominator[];
long long GCD(long long a,long long b){
    a=abs(a);
    b=abs(b);
    if(b==)
        return a;
    return GCD(b,a%b);

}
struct Fraction{
    long long integer;
    long long numerator;
    long long denominator;
}frac[];
/**
转化成带分数的形式
*/
void transfer(long long numerator,long long denominator,int i){
    //long long gcd=GCD(numerator,denominator);
    //numerator=numerator/gcd;
    //denominator=denominator/gcd;
    frac[i].integer=numerator/denominator;
    frac[i].numerator=numerator%denominator;
    frac[i].denominator=denominator;
}
/**
输出，如果为负数还要有括号
*/
void print(Fraction f){
    if(f.integer!=){
        if(f.integer<)
            printf("(");
        printf("%lld",f.integer);
    }

    if(f.numerator!=){
        if(f.integer!=){
            printf(" ");
        }
        //如果前面整数部分为0，则这里需要加(
        else if(f.numerator<)
            printf("(-");
        //注意，如果是负数，只要整数前面一个'-'就可以，所以这里不需要'-'
        if(f.numerator>)
            printf("%lld/%lld",f.numerator,f.denominator);
        else
            printf("%lld/%lld",-f.numerator,f.denominator);
    }
    if(f.integer==&&f.numerator==)
        printf("");
    else if(f.integer< || f.numerator<)
        printf(")"); //末尾补)
}

int main()
{
    long long res;
    scanf("%lld/%lld %lld/%lld",&numerator[],&denominator[],&numerator[],&denominator[]);
    //先约分
    long long gcd0=GCD(numerator[],denominator[]);
    numerator[]=numerator[]/gcd0;
    denominator[]=denominator[]/gcd0;
    long long gcd1=GCD(numerator[],denominator[]);

    numerator[]=numerator[]/gcd1;
    denominator[]=denominator[]/gcd1;

    long long gcd=GCD(denominator[],denominator[]);
    long long lcm=(denominator[]/gcd)*gcd*(denominator[]/gcd);
    transfer(numerator[],denominator[],);
    transfer(numerator[],denominator[],);
    //sum
    long long sum=numerator[]*(lcm/denominator[])+numerator[]*(lcm/denominator[]);
    long long gcd2=abs(GCD(sum,lcm));
    transfer(sum/gcd2,lcm/gcd2,);
    print(frac[]);
    printf(" + ");
    print(frac[]);
    printf(" = ");
    print(frac[]);
    printf("\n");

    //difference
    sum=numerator[]*(lcm/denominator[])-numerator[]*(lcm/denominator[]);
    gcd2=abs(GCD(sum,lcm));
    transfer(sum/gcd2,lcm/gcd2,);
    print(frac[]);
    printf(" - ");
    print(frac[]);
    printf(" = ");
    print(frac[]);
    printf("\n");

    //product
    sum=numerator[]*numerator[];
    res=denominator[]*denominator[];
    gcd2=abs(GCD(sum,res));
    transfer(sum/gcd2,res/gcd2,);
    print(frac[]);
    printf(" * ");
    print(frac[]);
    printf(" = ");
    print(frac[]);
    printf("\n");

    //quotient
    print(frac[]);
    printf(" / ");
    print(frac[]);
    printf(" = ");
    if(numerator[]==){
        printf("Inf\n");
    }
    else{
        sum=numerator[]*denominator[];
        res=denominator[]*numerator[];
        if(res<){
            sum=-sum;
            res=-res;
        }

        gcd2=abs(GCD(sum,res));
        transfer(sum/gcd2,res/gcd2,);

        print(frac[]);
        printf("\n");
    }

    return ;
}