P5734 【深基6.例6】文字处理软件

#include<cstdio> 
#include<iostream>
using namespace std;
int main(){
	int n;
	cin>>n;
	string s,s1,s2,s3,s4;
	cin>>s;
	for(int i=0;i<n;i++){
		int a0;
	    cin>>a0; 
		if(a0==1) {
		string b0;
		cin>>b0;
		s+=b0;
		cout<<s<<endl; 
		}
		else if(a0==2){
		int b,c;
	cin>>b>>c;
	s=s.substr(b,c);
	cout<<s<<endl;		
		}
		else if(a0==3) {
		int b1;
	string c1;
	cin>>b1>>c1;
	s=s.insert(b1,c1);
	cout<<s<<endl;		
		}
	 	else{
	 		string b2;
		    cin>>b2;
		    if(s.find(b2)<s.size())
			cout<<s.find(b2)<<endl;
			else
			cout<<"-1"<<endl; 
		 }
	}
	return 0;
}