#include using namespace std; int n; //n条指令 string s; //原来的字符串 string a; //要追加的字符串 int opt; //操作命令,1:追加,2:截取,3:插入,4:查找 int l; //从第几个开始截取 int cnt; //截取几个字符 int main() { cin >> n >> s; while (n--) { cin >> opt; switch (opt) { case 1: //追加 cin >> a; //s.append(a); s += a; cout << s << endl; break; case 2://截取 cin >> l >> cnt; s = s.substr(l, cnt); cout << s << endl; break; case 3: //插入 cin >> l >> a; s.insert(l, a); cout << s << endl; break; case 4: //查找位置 cin >> a; auto pos = s.find(a); if (pos == s.npos) printf("%d\n", -1); else printf("%d\n", pos); break; } } return 0; }