请大佬帮忙找一下什么问题

# include <iostream>
 using namespace std;
# include <string>
//char q[50];
string q;
string m;
//char m[50];
 int main()
 {
 	int n;
 	cin>>n;
 string p,k,z;
 	int d,c;

 	for(int i=0;i<n;i++)
 	{
 		cin>>p;
 		if(p=="a")
 		{
 			cin>>q>>m;
 				int d=stoi(q);
 					//cout<<"到这了" ;
 				int c=stoi(m);
 			int e=c+d;
 		string l=to_string(e);
 	//	cout<<l;
 				cout<<d<<"+"<<c<<"="<<d+c<<endl;
 				cout<<q.length()+m.length()+2+l.length()<<endl;
 					z=p;
		}
	else if(p=="b")
		{
				cin>>q>>m;
				int d=stoi(q);
 				int c=stoi(m);
 				string l=to_string(d-c);
 				cout<<d<<"-"<<c<<"="<<d-c<<endl;
 				cout<<q.length()+m.length()+2+l.length()<<endl;
				 	z=p;	
		}
		else if(p=="c")
		{
				cin>>q>>m;
				int d=stoi(q);
 				int c=stoi(m);
 				string l=to_string(d*c);
 				cout<<d<<"*"<<c<<"="<<d-c<<endl;
 				cout<<q.length()+m.length()+2+l.length()<<endl;	
 					z=p;
		}
 		else
 		{
 				if(z=="a")
 		{
 				cin>>m;
 				int d=stoi(p);
 				int c=stoi(m);
 		string l=to_string(c+d);
 			cout<<d<<"+"<<c<<"="<<d+c<<endl;
 			cout<<p.length()+m.length()+2+l.length()<<endl;
 				//	z=p;
		}
	else if(z=="b")
		{
			cin>>m;
				int d=stoi(p);
 				int c=stoi(m);
 				string l=to_string(d-c);
 				cout<<d<<"-"<<c<<"="<<d-c<<endl;
 				cout<<p.length()+m.length()+2+l.length()<<endl;
				 //	z=p;	
		}
		else if(z=="c")
		{
					cin>>m;
				int d=stoi(p);
 				int c=stoi(m);
 				string l=to_string(d*c);
 				cout<<d<<"*"<<c<<"="<<d*c<<endl;
 				cout<<p.length()+m.length()+2+l.length()<<endl;	
 				//	z=p;
		}
	
 		
		}
// 		cin>>a[i];
	
	 }
 //	cin>>a;
// 	int len=strlen(a);
// 	cout<<len;
// 	
 }