PAT A1081 分数计算

分数计算，之前做过相关的总结，这里不再赘述代码如下：
#include<iostream>
#include<stdlib.h>
#include<stdio.h>
#include<string>
using namespace std;
const int maxn=110;
typedef long long LL;
struct node{
LL up;
LL down;
};

LL str2num(string s){
LL sum=0;
for(int i=0;i<s.size();i++){
sum=sum*10+(s[i]-‘0’);
}
return sum;
}

int gcd(int a,int b){
if(b==0)
return a;
return gcd(b,a%b);
}

node reflesh(node a){
if(a.down<0){
a.up=-a.up;
a.down=-a.down;
}
if(a.up==0){
a.down=1;
}else{
int d;
if(abs(a.up)>abs(a.down)){
d=gcd(abs(a.up),abs(a.down));
}else{
d=gcd(abs(a.down),abs(a.up));
}
a.down/=d;
a.up/=d;
}
return a;
}

node add(node a,node b){
node result;
result.down=a.down*b.down;
result.up=a.up*b.down+a.down*b.up;
return reflesh(result);
}

void output(node a){
//reflesh(a);
if(a.down==1)
printf(“%lld\n”,a.up);
else if(abs(a.up)>a.down){
printf(“%lld %lld/%lld\n”,a.up/a.down,abs(a.up)%a.down,a.down);
}else{
printf(“%lld/%lld\n”,a.up,a.down);
}
}

int main(){
int N;
node f,s;
s.down=1;
s.up=0;
scanf(“%d”,&N);
for(int i=0;i<N;i++){
scanf(“%lld/%lld”,&f.up,&f.down);
s=add(s,f);
}
output(s);
system(“pause”);
return 0;
}