[백준 1543] 문서 검색 (JAVA) - S4

문제

https://www.acmicpc.net/problem/1543

1543번: 문서 검색

 

코드 1 (직접 구현)

import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        String target = br.readLine();
        String pattern = br.readLine();
        int cnt = 0;
        int i = 0;

        while(i <= target.length() - pattern.length()){
            if (target.substring(i, i + pattern.length()).equals(pattern)){
                cnt++;
                i += pattern.length();
            }
            else
                i++;
        }
        bw.write(String.valueOf(cnt));

        br.close();
        bw.flush();
        bw.close();
    }

}

 

코드 2 (다른 코드 참고 - StringBuilder 사용)

import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        StringBuilder sb = new StringBuilder();
        sb.append(br.readLine());

        String s = br.readLine();

        int cnt = 0, start = 0;
        int len = s.length();

        while((start = sb.toString().indexOf(s)) != -1){
            sb.delete(0, start + len);
            cnt++;
        }
        bw.write(String.valueOf(cnt));

        br.close();
        bw.flush();
        bw.close();
    }

}

1) StringBuilder

- indexOf(String str) : str이 등장하는 첫 index를 return

   -> 찾으려고 하는 str이 존재하지 않으면 -1을 return

 

- delete(int start, int end) : start ~ end - 1까지의 내용을 삭제