纯字符串方法模拟

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
public class Main {
	static BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
	static PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
	public static void main(String[] args) throws IOException {
		String m = in.readLine();
		int n = Integer.parseInt(in.readLine());
		for(int i=0;i<n;i++) {
			String[] s = in.readLine().split(" ");
			int start = Integer.parseInt(s[0]) - 1;
			int end = Integer.parseInt(s[1]) - 1;
			String jian = m.substring(start,end+1);
			m = m.substring(0, start) + m.substring(end+1);
			int index = m.indexOf(s[2]+s[3]);
			if(index==-1) 
				m = m + jian;
			else {
				index = index + s[2].length() - 1;
				m = m.substring(0,index+1) + jian + m.substring(index+1);
			}
		}
		out.println(m);
		out.flush();
	}
}