自测没问题

花花绿绿

#include<bits/stdc++.h>
using namespace std;

long long n, op, a, b;
string s, s1;

int main()
{
	cin >> n >> s;
	while(n--)
	{
		cin >> op;
		if(op == 1) cin >> s1, s += s1, cout << s << '\n';
		if(op == 2) cin >> a >> b, s = s.substr(a, b), cout << s << '\n';
		if(op == 3) cin >> a >> s1, s.insert(a, s1), cout << s << '\n';`
		if(op == 4) cin >> s1, cout << s.find(s1) << '\n';
	}
	return 0;
 }