1081. Rational Sum (20)

注意事项：1、注意特殊值0的输出 2、经过测试发现没用关于 负的假分数 的输出的测试点

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <cmath>

#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <map>
#include <set>

using namespace std;

struct node
{
    long long  up;
    long long down;
};

long long gcd(long a,long b)
{
    a=abs(a);
    b=abs(b);
    while(a%b!=0)
    {
        long long t=a%b;
        a=b;
        b=t;
    }

    return b;
}

node reduct(node a)
{
    long long t=gcd(a.up,a.down);
    a.up/=t;
    a.down/=t;

    return a;
}

node add(node a,node b)
{
    node tnode;
    tnode.up=b.down*a.up+a.down*b.up;
    tnode.down=a.down*b.down;
    tnode=reduct(tnode);

    return tnode;
}

void show(node a)
{
    if(a.up==0)
        printf("0");
    else
    if(abs(a.up)<a.down)
    {
        printf("%lld/%lld",a.up,a.down);
    }
    else if(abs(a.up)==a.down)
    {
        printf("%lld",a.up/a.down);
    }
    else//假分数
    {
        if(a.up%a.down==0)
            printf("%lld",a.up/a.down);
        else
            printf("%lld %lld/%lld",a.up/a.down,a.up%a.down,a.down);//***abs?
    }
}

int main()
{
  //  freopen("in.txt","r" ,stdin);

    node ans,tnode;
    ans.up=0;
    ans.down=1;
    int N;
    scanf("%d",&N);
    for(int i=0;i<N;i++)
    {
        scanf("%lld/%lld",&tnode.up,&tnode.down);
        ans=add(ans,tnode);
    }
    show(ans);

    return 0;
}