分数加减法

这题的关键是列出各种计算结果的情况：结果为0，结果为1，结果为整数。

我就是忘了结果为整数的情况导致一直AC不了#include <iostream>
#include <cstring>
#include <cmath>
#include <cstdlib>

const int MAX = 10;

using namespace std;

int getGCD(int a, int b)
{
if(a<b)
{
int t = a;
a = b;
b = t;
}
if(b==0)
return a;
else
return getGCD(b, a%b);
}

int main()
{
char ch[MAX];
while(cin.getline(ch,10))
{
int a0, b0, a1, b1;
char o;
a0 = atoi(ch);
char* p = strchr(ch, '/');
b0 = atoi(++p);
while(isdigit(*(++p)));
o = *p;
a1 = atoi(++p);
p = strchr(p, '/');
b1 = atoi(++p);

int n, m;
if(o=='+')
{
n = a0*b1+a1*b0;
m = b0*b1;
}
else if(o=='-')
{
n = a0*b1-a1*b0;
m = b0*b1;
}
if(n!=0)
{
if(n!=m)
{
int GCD = getGCD(fabs((double)m), fabs((double)n));
n/=GCD;
m/=GCD;
if(m!=1)
{
if(n>0&&m>0||n<0&&m<0)
cout<<n<<'/'<<m<<endl;
else
cout<<'-'<<fabs((double)n)<<'/'<<fabs((double)m)<<endl;
}
else cout<<n<<endl;
}
else
cout<<1<<endl;
}
else
cout<<0<<endl;
}
return 0;
}