60分代码，大佬求助错的都是RE

#include<bits/stdc++.h>
using namespace std;
int main(){
    char l[2],s[105];
    int n,b,c;
    char a;
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>l;
        if(l[0]>='a'&&l[0]<='z'){
            a=l[0];
            cin>>b>>c;
        }else{
            sscanf(l,"%d",b);
            cin>>c;
        }
        memset(s,0,sizeof(s));
        if(a=='a'){
            sprintf(s,"%d+%d=%d",b,c,b+c);
        }else if(a=='b'){
            sprintf(s,"%d-%d=%d",b,c,b-c);
        }else if(a=='c'){
            sprintf(s,"%d*%d=%d",b,c,b*c);
        }else sprintf(s,"%d+%d=%d",b,b,b+c);
        cout<<s<<endl<<strlen(s)<<endl;
    }
}