diff --git "a/2022/Oct/week_1/leetCode_3sum_\352\262\275\355\230\234\354\225\210.java" "b/2022/Oct/week_1/leetCode_3sum_\352\262\275\355\230\234\354\225\210.java"
new file mode 100644
index 0000000..007fdd2
--- /dev/null
+++ "b/2022/Oct/week_1/leetCode_3sum_\352\262\275\355\230\234\354\225\210.java"
@@ -0,0 +1,46 @@
+package Oct;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class leetCode_3sum_경혜안 {
+	
+	public static void main(String[] args) {
+		int[] nums = {-1,0,1,2,-1,-4};
+		
+		List<List<Integer>> ans = new ArrayList<List<Integer>>();
+		
+		Arrays.sort(nums);
+		int len = nums.length;
+		for (int i = 0; i < len - 2; i++) {
+			if(i > 0 && nums[i] == nums[i-1]) continue;
+			
+			int start = i + 1;
+			int end = len - 1;
+			
+			while (start < end) {
+				int sum = nums[i] + nums[start] + nums[end];
+				
+				if(sum == 0) {
+					ans.add(Arrays.asList(nums[i], nums[start], nums[end]));
+					start++;
+					end--;
+					
+					while(nums[start] == nums[start-1] && start < end) start++;
+					while(nums[end] == nums[end+1] && start < end) end--;
+				} else if (sum > 0) {
+					end--;
+				} else {
+					start++;
+				}
+						 
+			}
+		}
+		
+		
+	}
+	
+	
+
+}
diff --git "a/2022/Oct/week_1/\355\224\204\353\241\234\352\267\270\353\236\230\353\250\270\354\212\244_lv2_\355\233\204\353\263\264\355\202\244_\352\262\275\355\230\234\354\225\210.java" "b/2022/Oct/week_1/\355\224\204\353\241\234\352\267\270\353\236\230\353\250\270\354\212\244_lv2_\355\233\204\353\263\264\355\202\244_\352\262\275\355\230\234\354\225\210.java"
new file mode 100644
index 0000000..8942d85
--- /dev/null
+++ "b/2022/Oct/week_1/\355\224\204\353\241\234\352\267\270\353\236\230\353\250\270\354\212\244_lv2_\355\233\204\353\263\264\355\202\244_\352\262\275\355\230\234\354\225\210.java"
@@ -0,0 +1,79 @@
+package Oct;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
+
+public class 프로그래머스_lv2_후보키_경혜안 {
+	static ArrayList<String> answer;
+	static String[][] rel;
+	public static void main(String[] args) {
+		
+		String[][] relation = {{"100","ryan","music","2"},{"200","apeach","math","2"},{"300","tube","computer","3"},{"400","con","computer","4"},{"500","muzi","music","3"},{"600","apeach","music","2"}};
+		rel = relation;
+		answer = new ArrayList<String>();
+		
+		int[] arr = new int[relation[0].length];
+		
+		for (int i = 0; i < relation[0].length; i++) arr[i] = i;
+		
+		for (int i = 1; i <= relation[0].length; i++) {
+			Comb(arr, new boolean[relation[0].length], 0, i);
+		}
+		
+		System.out.println(answer.size());
+
+	}
+	
+	static void Comb(int[] arr, boolean[] visited, int start, int d ) {
+		
+		if( d == 0) {
+			StringBuilder sb = new StringBuilder();
+
+			for (int i = 0; i < visited.length; i++) {
+				if(visited[i]) sb.append("1"); else sb.append("0");
+
+			}
+
+			int temp = Integer.parseInt(sb.toString(), 2);
+			for (String a : answer) {
+				if((temp & Integer.parseInt(a)) == Integer.parseInt(a)) {
+					return;
+				}
+			}
+			
+			if(isPk(visited)) {
+				answer.add(Integer.toString(temp));
+			}
+			
+			
+			
+		}
+		else {
+			for (int i = start; i < visited.length; i++) {
+				visited[i] = true;
+				Comb(arr, visited, i+1, d-1);
+				visited[i] = false;
+			}
+		}
+	}
+	
+	static boolean isPk(boolean[] visited) {
+		Set<String> list = new HashSet<String>();
+		
+		for (int i = 0; i < rel.length; i++) {
+			StringBuilder sb = new StringBuilder();
+			for (int j = 0; j < visited.length; j++) {
+				if(visited[j]) {
+					sb.append(rel[i][j]);
+				}
+			}
+			list.add(sb.toString());
+		}
+		
+		if(list.size() == rel.length) return true;
+		return false;
+	}
+	
+
+}