模板

1.分数的表示与分数的运算

#include <iostream>
#include <cstring>
#include <algorithm>
#include <vector>

using namespace std ;

struct Fraction{//分数的定义 
    int up, down ;
};

int gcd(int a,int b){
    return b ? gcd(b,a%b) : a ;
}

Fraction reduction(Fraction ft){//化为最简分数 
    if(ft.down<0){
        ft.up = -ft.up ;
        ft.down = -ft.down ;
    }
    if(ft.up == 0){
        ft.down = 1 ;
    }else{
        int d = gcd(ft.up,ft.down) ;
        ft.up /= d ;
        ft.down /= d ;
    }
    return ft ;
}

Fraction add(Fraction ft1,Fraction ft2){//加 
    Fraction res ;
    res.up = ft1.up*ft2.down + ft1.down*ft2.up ;
    res.down = ft1.down*ft2.down ;
    return res ;
}

Fraction sub(Fraction ft1,Fraction ft2){//减 
    Fraction res ;
    res.up = ft1.up*ft2.down - ft1.down*ft2.up ;
    res.down = ft1.down*ft2.down ;
    return res ;
}

Fraction mul(Fraction ft1,Fraction ft2){//乘 
    Fraction res ;
    res.up = ft1.up*ft2.up ;
    res.down = ft1.down*ft2.down ;
    return res ;
}

Fraction div(Fraction ft1,Fraction ft2){//除(需要特判除数是否为0) 
    Fraction res ;
    res.up = ft1.up*ft2.down ;
    res.down = ft1.down*ft2.up ;
    return res ; 
}

void ShowResult(Fraction ft){//输出分数 
    ft = reduction(ft) ;
    if(ft.down == 1){
        printf("%lld",ft.up) ;
    }else if(abs(ft.up>ft.down)){
        printf("%d %d/%d",ft.up/ft.down,abs(ft.up)%ft.down,ft.down) ;
    }else{
        printf("%d/%d",ft.up,ft.down) ;
    }
}

int main(){
    
    
    return 0 ;    
}