고양이와 개는 몇 마리 있을까 # (1) SELECT ANIMAL_TYPE as TYPE, COUNT(ANIMAL_TYPE) as COUNT FROM ANIMAL_INS WHERE ANIMAL_TYPE IN ('Dog', 'Cat') GROUP BY ANIMAL_TYPE # (2) SELECT ANIMAL_TYPE, COUNT(ANIMAL_TYPE) as count FROM ANIMAL_INS GROUP BY ANIMAL_TYPE ORDER BY ANIMAL_TYPE 동명 동물 수 찾기 SELECT t1.NAME, t1.COUNT FROM (SELECT NAME, COUNT(NAME) as COUNT FROM ANIMAL_INS WHERE NAME IS NOT NULL GROUP BY NAME) as t..

최댓값 구하기 # Using filesort SELECT DATETIME FROM ANIMAL_INS ORDER BY DATETIME DESC LIMIT 1 SELECT MAX(DATETIME) FROM ANIMAL_INS 최솟값 구하기 # -> Aggregate: min(animal_ins.`DATETIME`) -> Table scan on ANIMAL_INS (cost=10.25 rows=100) SELECT MIN(DATETIME) FROM ANIMAL_INS 동물 수 구하기 SELECT COUNT(1) FROM ANIMAL_INS 중복 제거하기 SELECT COUNT(DISTINCT NAME) FROM ANIMAL_INS

모든 레코드 조회하기 SELECT * FROM ANIMAL_INS ORDER BY ANIMAL_ID 역순 정렬하기 SELECT NAME, DATETIME FROM ANIMAL_INS ORDER BY ANIMAL_ID DESC # Backward index scan 아픈 동물 찾기 SELECT ANIMAL_ID, NAME FROM ANIMAL_INS WHERE INTAKE_CONDITION LIKE "Sick" ORDER BY ANIMAL_ID 어린 동물 찾기 SELECT ANIMAL_ID, NAME FROM ANIMAL_INS WHERE INTAKE_CONDITION "Aged" ORDER BY ANIMAL_ID 동물의 아이디와 이름 SELECT ANIMAL_ID, NAME FROM ANIMAL_INS ..

접근 방식 브루트포스 방식으로 모든 지점에 대해서 BFS 탐색 시도한 코드 package boj; import java.io.BufferedReader; import java.io.InputStreamReader; import java.util.ArrayDeque; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Objects; import java.util.Queue; import java.util.StringTokenizer; public class EscapeRoom { private static int[][] map; private static final int[] dx = {0,..

import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); int n = scanner.nextInt(); int m = scanner.nextInt(); System.out.print(m - gcd(n, m)); scanner.close(); } private static int gcd(int a, int b) { if (b == 0) { return a; } return gcd(b, a % b); } }

import java.io.BufferedReader; import java.io.InputStreamReader; import java.util.ArrayDeque; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Queue; import java.util.StringTokenizer; import java.util.Vector; import java.util.stream.Collectors; public class Main { private static final List graph = new ArrayList(); private static int[] indegree = null; ..