全WA，样例能过，求指点

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
string s;
int n,l;
int ans=2,i;
int a,b;
char x;
void init()
{
    a=0;
    b=0;
    ans=2;
    i=0;
}
void add()
{
    //printf("%d+%d=%d\n",a,b,a+b);
    cout<<a<<"+"<<b<<"="<<a+b<<endl;
    int c=a+b;
    while(c!=0)
    {
        c/=10;
        ans++;
    }
    //printf("%d\n",ans);
    cout<<ans<<endl;
}
void reduce()
{
    //printf("%d-%d=%d\n",a,b,a-b);
    cout<<a<<"-"<<b<<"="<<a-b<<endl;
    int c=a+b;
    if(c<=0)ans++;
    while(c!=0)
    {
        c/=10;
        ans++;
    }
    //printf("%d\n",ans);
    cout<<ans<<endl;
}
void mutiply()
{
    //printf("%d*%d=%d\n",a,b,a*b);
    cout<<a<<"*"<<b<<"="<<a*b<<endl;
    long long c=a*b;
    while(c!=0)
    {
        c/=10;
        ans++;
    }
    //printf("%d\n",ans);
    cout<<ans<<endl;
}
int main()
{
    cin>>n;
    while(n--)
    {
        init();
        getline(cin,s);
        l=s.length();
        if(s[0]>='a'&&s[0]<='c')x=s[0],i=2;
        for(;i<l;i++)
        {
            if(s[i]==' ')break;
            a*=10;
            a+=s[i]-48;
            ans++;
        }
        for(i+=1;i<l;i++)
        {
            b*=10;
            b+=s[i]-48;
            ans++;
        }
        switch(x)
        {
            case 'a':
                add();
                break;
            case 'b':
                reduce();
                break;
            case 'c':
                mutiply();
                break;
        }
    }
    return 0;
}