diff --git "a/BOJ/1000-5000\353\262\210/JY_1707.java" "b/BOJ/1000-5000\353\262\210/JY_1707.java"
new file mode 100644
index 00000000..db3a593d
--- /dev/null
+++ "b/BOJ/1000-5000\353\262\210/JY_1707.java"
@@ -0,0 +1,73 @@
+import java.io.*;
+import java.util.*;
+public class JY_1707 {
+	
+	static int T, N, M;
+	static List<Integer>[] g;
+	static boolean[] visited;
+	static int[] crr;
+	static boolean isOk;
+
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		
+		T = Integer.parseInt(st.nextToken());
+		StringBuilder sb = new StringBuilder();
+		for(int t=0; t<T; t++) {
+			st = new StringTokenizer(br.readLine());
+			N = Integer.parseInt(st.nextToken());
+			M = Integer.parseInt(st.nextToken());
+			
+			g = new ArrayList[N+1];
+			for(int i=1; i<N+1; i++) {
+				g[i] = new ArrayList<>();
+			}
+			
+			for(int i=0; i<M; i++) {
+				st = new StringTokenizer(br.readLine());
+				int a = Integer.parseInt(st.nextToken());
+				int b = Integer.parseInt(st.nextToken());
+				g[a].add(b);
+				g[b].add(a);
+			}
+			
+			visited = new boolean[N+1];
+			crr = new int[N+1];	// 집합 번호 저장 배열
+			isOk = true;
+			for(int i=1; i<N+1; i++) {
+				if(visited[i]) continue;
+				dfs(i, 1);
+				if(!isOk) break;
+				
+			}
+			
+			if(isOk) sb.append("YES\n");
+			else sb.append("NO\n");
+				
+		}
+		
+		System.out.println(sb.toString());
+
+	}
+	public static void dfs(int now, int group) {
+		crr[now] = group;
+		visited[now] = true;
+		
+		for(int next: g[now]) {
+			// 인접 노드가 현재 노드의 그룹과 같다면 fail
+			if(crr[next] == group) {
+				isOk = false;
+				return;
+			}
+			
+			// 방문 X
+			if(!visited[next]) {
+				dfs(next, -group);
+			}
+			
+		}
+	}
+
+
+}
diff --git "a/BOJ/15001-20000\353\262\210/JY_16724.java" "b/BOJ/15001-20000\353\262\210/JY_16724.java"
new file mode 100644
index 00000000..3cefe178
--- /dev/null
+++ "b/BOJ/15001-20000\353\262\210/JY_16724.java"
@@ -0,0 +1,75 @@
+import java.io.*;
+import java.util.*;
+public class JY_16724 {
+	
+	static int N, M;
+	static char[][] g;
+	static int[] parent;
+	// 상 하 좌 우
+	static int[] dx = {-1, 1, 0, 0};
+	static int[] dy = {0, 0, -1, 1};
+	static Map<Character, Integer> cMap;
+
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		
+		N = Integer.parseInt(st.nextToken());
+		M = Integer.parseInt(st.nextToken());
+		g = new char[N][M];
+		
+		parent = new int[N*M];
+		for(int i=0; i<N; i++) {
+			String line = br.readLine();
+			for(int j=0; j<M; j++) {
+				g[i][j] = line.charAt(j);
+				parent[i*M+j] = i*M+j;
+			}
+		}
+		
+		cMap = new HashMap<>();
+		cMap.put('U', 0);
+		cMap.put('D', 1);
+		cMap.put('L', 2);
+		cMap.put('R', 3);
+		
+		for(int i=0; i<N; i++) {
+			for(int j=0; j<M; j++) {
+				int dir = cMap.get(g[i][j]);
+				int nx = i + dx[dir];
+				int ny = j + dy[dir];
+				if(find(i*M+j) != find(nx*M+ny)) {
+					union(i*M+j, nx*M+ny);
+				}
+			}
+		} 
+		
+		Set<Integer> cSet = new HashSet<>();
+		for(int i=0; i<N*M; i++) {
+			// a <- b <- c 관계에서 모두 parent 값은 a인데
+			// a의 parent 값이 변경되면 b, c는 변경되지 않으므로 경로압축을 통한 최종 부모를 찾아줘야 함
+			// ** 최종 부모를 찾아주기 위해서 find()후 삽입
+			cSet.add(find(parent[i]));
+		}
+		System.out.println(cSet.size());
+		
+
+	}
+	public static int find(int x) {
+		if(x != parent[x]) {
+			parent[x] = find(parent[x]);
+		}
+		return parent[x];
+	}
+	public static void union(int a, int b) {
+		int pa = find(a);
+		int pb = find(b);
+		
+		if(pa < pb) {
+			parent[pb] = pa;
+		} else {
+			parent[pa] = pb;
+		}
+	}
+
+}
diff --git "a/BOJ/15001-20000\353\262\210/JY_18430.java" "b/BOJ/15001-20000\353\262\210/JY_18430.java"
new file mode 100644
index 00000000..e852d771
--- /dev/null
+++ "b/BOJ/15001-20000\353\262\210/JY_18430.java"
@@ -0,0 +1,72 @@
+import java.io.*;
+import java.util.*;
+
+public class JY_18430 {
+	
+	static int N, M;
+	static int[][] g;
+	// 상 좌 하 우
+	static int[] dx = {-1, 0, 1, 0};
+	static int[] dy = {0, -1, 0, 1};
+	static boolean[][] visited;
+	static int ans;
+
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		
+		N = Integer.parseInt(st.nextToken());
+		M = Integer.parseInt(st.nextToken());
+		
+		g = new int[N][M];
+		for(int i=0; i<N; i++) {
+			st = new StringTokenizer(br.readLine());
+			for(int j=0; j<M; j++) {
+				g[i][j] = Integer.parseInt(st.nextToken());
+			}
+		}
+		
+		visited = new boolean[N][M];
+		ans = 0;
+		dfs(0, 0, 0);
+		
+		System.out.println(ans);
+	}
+	public static boolean inRange(int x, int y) {
+		return x>=0 && x<N && y>=0 && y<M;
+	}
+	public static void dfs(int x, int y, int score) {
+		// 다음 행 진행
+		if(y == M) {
+			x += 1;
+			y = 0;
+		}
+		if(x == N) {
+			ans = Math.max(ans, score);
+			return;
+		}
+		// (x, y) 방문 O
+		if(!visited[x][y]) {
+			// 부메랑 반복
+			for(int d=0; d<4; d++) {
+				int ax = x + dx[d];
+				int ay = y + dy[d];
+				int bx = x + dx[(d+1)%4];
+				int by = y + dy[(d+1)%4];
+				if(!inRange(ax, ay) || !inRange(bx, by)) continue;
+				if(visited[ax][ay] || visited[bx][by]) continue;
+				visited[x][y] = true;
+				visited[ax][ay] = true;
+				visited[bx][by] = true;
+				dfs(x,y+1, score + (g[x][y]*2 +g[ax][ay] + g[bx][by]));
+				visited[x][y] = false;
+				visited[ax][ay] = false;
+				visited[bx][by] = false;
+			}			
+		}
+		// (x, y) 방문 X
+		dfs(x, y+1, score);
+
+	}
+
+}
diff --git "a/CodeTree/2017-2018\353\205\204/JY_\353\263\221\354\233\220_\352\261\260\353\246\254_\354\265\234\354\206\214\355\231\224\355\225\230\352\270\260.java" "b/CodeTree/2017-2018\353\205\204/JY_\353\263\221\354\233\220_\352\261\260\353\246\254_\354\265\234\354\206\214\355\231\224\355\225\230\352\270\260.java"
new file mode 100644
index 00000000..aee25d59
--- /dev/null
+++ "b/CodeTree/2017-2018\353\205\204/JY_\353\263\221\354\233\220_\352\261\260\353\246\254_\354\265\234\354\206\214\355\231\224\355\225\230\352\270\260.java"
@@ -0,0 +1,90 @@
+import java.io.*;
+import java.util.*;
+public class JY_병원_거리_최소화하기 {
+	
+	static int N, M;
+	static int[][] g;
+	static Map<Integer, Hospital> hMap;
+	static List<Integer> tList;
+	static int ans;
+	static class Hospital {
+		int num, x, y;
+
+		public Hospital(int num, int x, int y) {
+			super();
+			this.num = num;
+			this.x = x;
+			this.y = y;
+		}
+
+		@Override
+		public String toString() {
+			return "Hospital [num=" + num + ", x=" + x + ", y=" + y + "]";
+		}
+		
+	}
+
+	public static void main(String[] args) throws IOException{
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		
+		N = Integer.parseInt(st.nextToken());
+		M = Integer.parseInt(st.nextToken());
+		
+		g = new int[N][N];
+		hMap = new HashMap<>();
+		int n = 0;
+		for(int i=0; i<N; i++) {
+			st = new StringTokenizer(br.readLine());
+			for(int j=0; j<N; j++) {
+				g[i][j] = Integer.parseInt(st.nextToken());
+				if(g[i][j] == 2) {
+					hMap.put(n, new Hospital(n, i, j));
+					n++;
+				}
+			}
+		}
+		
+		tList = new ArrayList<>();
+		ans = Integer.MAX_VALUE;
+		// 최대 경우의 수 : 100(사람수) * 13C7 * 7
+		comb(0, 0);
+		
+		System.out.println(ans);
+	}
+	public static void comb(int depth, int start) {
+		if(depth == M) {
+			int score = find(tList);
+			ans = Math.min(ans, score);
+			return;
+		}
+		for(int i=start; i<hMap.size(); i++) {
+			tList.add(i);
+			comb(depth+1, i+1);
+			tList.remove(tList.size()-1);
+		}
+	}
+	public static int cal(int x1, int y1, int x2, int y2) {
+		return Math.abs(x1-x2) + Math.abs(y1-y2);
+	}
+	public static int find(List<Integer> hList) {
+		int total = 0;
+		// 사람 반복
+		for(int i=0; i<N; i++) {
+			for(int j=0; j<N; j++) {
+				if(g[i][j] != 1) continue;
+				int tmp = Integer.MAX_VALUE; 
+				// 병원 반복
+				for(int h : hList) {
+					Hospital now = hMap.get(h);
+					int dist = cal(i, j, now.x, now.y);
+					tmp = Math.min(tmp, dist);
+				}
+				total += tmp;
+			}
+		}
+		
+		return total;
+	}
+
+}
diff --git a/Programmers/Level3/JY_67258.java b/Programmers/Level3/JY_67258.java
new file mode 100644
index 00000000..d2b9b7be
--- /dev/null
+++ b/Programmers/Level3/JY_67258.java
@@ -0,0 +1,46 @@
+import java.util.*;
+class JY_67258 {
+    public int[] solution(String[] gems) {
+        int[] answer = new int[2];
+        
+        // 총 보석 종류구하기
+        Set<String> gSet = new HashSet<>();
+        for(String g: gems) {
+            gSet.add(g);
+        }
+        int total = gSet.size();
+        
+        
+        int minR = Integer.MAX_VALUE;
+        // 투포인터 활용
+        int s = 0;
+        int e = s;
+        Map<String, Integer> gMap = new HashMap<>();
+        while(e < gems.length) {
+            // System.out.println(">> now: "+gMap+", s:"+s+",e:"+e);
+            // 보석 추가
+            gMap.put(gems[e], gMap.getOrDefault(gems[e], 0)+1);
+            
+            // 현재 구간(gMap의 보석들)이 모든 보석을 포함함
+            // 총 보석의 개수가 total보다 작을 떄까지 s증가 
+            while(gMap.keySet().size() == total) {
+                // 더 짧은 구간
+                if(minR > (e-s)) {
+                    minR = (e-s);
+                    answer[0] = s+1;
+                    answer[1] = e+1;
+                }   
+                // s지점의 보석 감소
+                gMap.put(gems[s], gMap.get(gems[s])-1);
+                // 감소 후, gems[s]의 개수가 0이된다면 gMap에서 삭제
+                if(gMap.get(gems[s]) == 0) gMap.remove(gems[s]);
+                s++;
+            } 
+            
+            e++;
+            
+        }
+        
+        return answer;
+    }
+}
\ No newline at end of file
diff --git "a/SQL/22\354\243\274\354\260\250/JY_\354\213\235\355\222\210\353\266\204\353\245\230\353\263\204_\352\260\200\354\236\245_\353\271\204\354\213\274_\354\213\235\355\222\210\354\235\230_\354\240\225\353\263\264_\354\241\260\355\232\214\355\225\230\352\270\260.sql" "b/SQL/22\354\243\274\354\260\250/JY_\354\213\235\355\222\210\353\266\204\353\245\230\353\263\204_\352\260\200\354\236\245_\353\271\204\354\213\274_\354\213\235\355\222\210\354\235\230_\354\240\225\353\263\264_\354\241\260\355\232\214\355\225\230\352\270\260.sql"
new file mode 100644
index 00000000..dcda9147
--- /dev/null
+++ "b/SQL/22\354\243\274\354\260\250/JY_\354\213\235\355\222\210\353\266\204\353\245\230\353\263\204_\352\260\200\354\236\245_\353\271\204\354\213\274_\354\213\235\355\222\210\354\235\230_\354\240\225\353\263\264_\354\241\260\355\232\214\355\225\230\352\270\260.sql"
@@ -0,0 +1,11 @@
+-- 식품분류별 가장 비싼 식품의 정보 조회하기
+-- https://school.programmers.co.kr/learn/courses/30/lessons/131116
+SELECT CATEGORY, PRICE AS MAX_PRICE, PRODUCT_NAME
+FROM FOOD_PRODUCT
+WHERE (CATEGORY, PRICE) IN (
+    SELECT CATEGORY, MAX(PRICE)
+    FROM FOOD_PRODUCT
+    WHERE CATEGORY IN('과자', '국', '김치', '식용유')
+    GROUP BY CATEGORY
+)
+ORDER BY MAX_PRICE DESC
\ No newline at end of file