20分求助

#include<bits/stdc++.h>
using namespace std;
char s;
long long ikun,a1,a2,a3,l=2;
int main(){
	//freopen("口算练习题.in","r",stdin);
	//freopen("口算练习题.out","w",stdout);
	cin>>ikun;
	for(int i=0;i<ikun;i++){
		l=2;
		cin>>s;
		if(islower(s))cin>>a1>>a2;
		else{
			a1=int(s);
			cin>>a2;
		}
		if(s=='a'){
			a3=a1+a2;
			cout<<a1<<"+"<<a2<<"="<<a1+a2<<endl;
			while(a1){
				l++;
				a1/=10;
			}
			while(a2){
				l++;
				a2/=10;
			}
			while(a3){
				l++;
				a3/=10;
			}
			cout<<l<<endl;
		}
		if(s=='b'){
			a3=a1-a2;
			cout<<a1<<"-"<<a2<<"="<<a1-a2<<endl;
			while(a1){
				l++;
				a1/=10;
			}
			while(a2){
				l++;
				a2/=10;
			}
			while(a3){
				l++;
				a3/=10;
			}
			cout<<l<<endl;
		}
		if(s=='c'){
			a3=a1*a2;
			cout<<a1<<"*"<<a2<<"="<<a1*a2<<endl;;
			while(a1){
				l++;
				a1/=10;
			}
			while(a2){
				l++;
				a2/=10;
			}
			while(a3){
				l++;
				a3/=10;
			}
			cout<<l<<endl;
		}
	}
	return 0;
}