三个WA和两个RE

#include <bits/stdc++.h>
using namespace std;
int q;
string s;
int main()
{
    // freopen("code.in", "r", stdin);
    // freopen("code.out", "w", stdout);
    cin >> q >> s;
    while (q--)
    {
        int m;
        cin >> m;
        switch (m)
        {
        case 1:
        {
            string k;
            cin >> k;
            s += k;
            cout << s << endl;
            break;
        }
        case 2:
        {
            int a, b;
            cin >> a >> b;
            s = s.substr(a, b);
            cout << s << endl;
            break;
        }
        case 3:
        {
            int a;
            string k;
            cin >> a >> k;
            s.insert(a - 1, k);
            cout << s << endl;
            break;
        }
        case 4:
        {
            string k;
            cin >> k;
            cout << (s.find(k) == string::npos ? -1 : s.find(k) + 1) << endl;
        }
        }
    }
    // fclose(stdin);
    // fclose(stdout);
    return 0;
}