[BaekJoon] 1269번 대칭 차집합 문제 풀이 (Success)

1269번: 대칭 차집합

 

☕Language: Java

 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeSet;
 
public class Main {
 
    public static void main(String[] args) throws IOException {
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 
        StringTokenizer st = new StringTokenizer(br.readLine());
 
        int N = Integer.parseInt(st.nextToken());
        int M = Integer.parseInt(st.nextToken());
 
        Set<Integer> set1 = new TreeSet<>();
        StringTokenizer stN = new StringTokenizer(br.readLine());
        while (N-- > 0) {
            set1.add(Integer.parseInt(stN.nextToken()));
        }
 
        Set<Integer> set2 = new TreeSet<>();
        StringTokenizer stM = new StringTokenizer(br.readLine());
        while (M-- > 0) {
            set2.add(Integer.parseInt(stM.nextToken()));
        }
 
        int A = return_size(set1, set2);
        int B = return_size(set2, set1);
 
        bw.write((A + B) + "");
 
        bw.flush();
        bw.close();
 
    }
 
    public static int return_size(Set<Integer> set1, Set<Integer> set2) {
        int cnt = 0;
        for (int i : set2) {
            if (!set1.contains(i)) {
                cnt++;
            }
 
        }
 
        return cnt;
    }
 
}
 

🤔 해설

1. set1.add(Integer.parseInt(stN.nextToken()));

    - 첫 번째 입력값을 set1에 저장

 

2. set2.add(Integer.parseInt(stM.nextToken()));

    - 두 번째 입력값을 set2에 저장

 

3. if (!set1.contains(i)) { cnt++; }

    - set2 요소 값이 set1에 있을 경우, cnt 증가 후 return

 

😮 이 외의 풀이

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.HashSet;
import java.util.Set;
import java.util.StringTokenizer;
 
public class Main {
 
    static StringTokenizer st;
 
    public static void main(String[] args) throws IOException {
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 
        st = new StringTokenizer(br.readLine());
 
        int N = Integer.parseInt(st.nextToken());
        int M = Integer.parseInt(st.nextToken());
 
        st = new StringTokenizer(br.readLine());
        Set<Integer> set = new HashSet<>();
        for (int i = 0; i < N; i++) {
            set.add(Integer.valueOf(st.nextToken()));
        }
 
        st = new StringTokenizer(br.readLine());
        int cnt = 0;
        for (int i = 0; i < M; i++) {
            int num = Integer.valueOf(st.nextToken());
            cnt = set.contains(num) ? cnt + 1 : cnt;
            set.add(num);
        }
 
        bw.write((set.size() - cnt) + "");
 
        bw.flush();
        bw.close();
 
    }
 
}
 

1. static StringTokenizer st;

    - StringTokenizer 전역 변수 선언

 

2. cnt = set.contains(num) ? cnt + 1 : cnt;

    - cnt: 입력값1과 입력값2의 공통 요소 개수

 

3. bw.write((set.size() - cnt) + "");

    - 중복이 제거된 set에서 중복된 값인 cnt 차감

 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.HashSet;
import java.util.Set;
import java.util.StringTokenizer;
 
public class Main {
 
    static StringTokenizer st;
 
    public static void main(String[] args) throws IOException {
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 
        StringTokenizer st;
 
        st = new StringTokenizer(br.readLine());
 
        int N = Integer.parseInt(st.nextToken());
        int M = Integer.parseInt(st.nextToken());
 
        Set<Integer> setN = new HashSet<>();
        Set<Integer> setM = new HashSet<>();
 
        st = new StringTokenizer(br.readLine());
        for (int i = 0; i < N; i++) {
            setN.add(Integer.parseInt(st.nextToken()));
        }
 
        st = new StringTokenizer(br.readLine());
        for (int i = 0; i < M; i++) {
            setM.add(Integer.parseInt(st.nextToken()));
        }
 
        int cnt = 0;
        for (int i : setN) {
            cnt = !setM.contains(i) ? cnt + 1 : cnt;
        }
        for (int i : setM) {
            cnt = !setN.contains(i) ? cnt + 1 : cnt;
        }
 
        bw.write(cnt + "");
 
        bw.flush();
        bw.close();
 
    }
 
}
 

 

 

 

🔗 소스 코드
GitHub

 

📚 참고 자료

[BOJ] 1269 - 대칭 차집합 JAVA