diff --git a/code_study/Baekjoon/java/_1005_1.java b/code_study/Baekjoon/java/_1005_1.java
new file mode 100644
index 0000000..4713663
--- /dev/null
+++ b/code_study/Baekjoon/java/_1005_1.java
@@ -0,0 +1,59 @@
+import java.util.*;
+
+public class _1005_1 {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int T = sc.nextInt();
+        int[] ans = new int[T];
+
+        for(int t=0; t<T; t++) {
+            int N = sc.nextInt(), K = sc.nextInt();
+
+            int[] build_time = new int[N+1];
+            for(int i=1; i<=N; i++) build_time[i] = sc.nextInt();
+
+            int[] indegree = new int[N+1];
+            int[][] graph = new int[N+1][N+1];
+
+            for(int i=0; i<K; i++) {
+                int X = sc.nextInt(), Y = sc.nextInt();
+                indegree[Y]++;
+                graph[X][++graph[X][0]] = Y;
+            }
+
+            int W = sc.nextInt();
+            int[] complete_time = new int[N+1];
+            int[] qu = new int[N];
+            int front = 0, rear = 0;
+            for(int i=1; i<=N; i++) {
+                if(indegree[i] == 0) {
+                    qu[rear++] = i;
+                    complete_time[i] = build_time[i];
+                }
+            }
+
+            while(front <= rear) {
+                int now = qu[front++];
+                if(now == W) break;
+
+                for(int i=1; i<=graph[now][0]; i++) {
+                    int next = graph[now][i];
+                    indegree[next]--;
+                    complete_time[next] = Math.max(complete_time[now] + build_time[next], complete_time[next]);
+
+                    if(indegree[next] == 0) {
+                        qu[rear++] = next;
+                    }
+                }
+            }
+
+            ans[t] = complete_time[W];
+        }
+        
+        sc.close();
+
+        for (int n : ans) {
+            System.out.println(n);
+        }
+    }
+}
diff --git a/code_study/Baekjoon/java/_1005_2.java b/code_study/Baekjoon/java/_1005_2.java
new file mode 100644
index 0000000..703920e
--- /dev/null
+++ b/code_study/Baekjoon/java/_1005_2.java
@@ -0,0 +1,55 @@
+import java.util.*;
+
+public class _1005_2 {
+    static int N, K, W;
+    static int[] build_time, complete_time;
+    static int[][] prev_build;
+
+    static int build(int n) {
+        if(complete_time[n] == -1) {
+            int total_time = 0;
+            for(int i=1; i<=prev_build[n][0]; i++) {
+                int prev = prev_build[n][i];
+                total_time = Math.max(total_time, build(prev));
+            }
+            complete_time[n] = total_time + build_time[n];
+        }
+
+        return complete_time[n];
+    }
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int T = sc.nextInt();
+        int[] ans = new int[T];
+
+        for(int t=0; t<T; t++) {
+            N = sc.nextInt();
+            K = sc.nextInt();
+
+            build_time = new int[N+1];
+            for(int i=1; i<=N; i++) {
+                build_time[i] = sc.nextInt();
+            }
+
+            prev_build = new int[N+1][N+1];
+
+            for(int i=0; i<K; i++) {
+                int X = sc.nextInt(), Y = sc.nextInt();
+                prev_build[Y][++prev_build[Y][0]] = X;
+            }
+
+            complete_time = new int[N+1];
+            for(int i=1; i<=N; i++) complete_time[i] = -1;
+
+            W = sc.nextInt();
+
+            ans[t] = build(W);
+        }
+        
+        sc.close();
+
+        for (int n : ans) {
+            System.out.println(n);
+        }
+    }
+}
\ No newline at end of file
diff --git a/code_study/Baekjoon/swift/3460.swift b/code_study/Baekjoon/swift/3460.swift
new file mode 100644
index 0000000..fd70054
--- /dev/null
+++ b/code_study/Baekjoon/swift/3460.swift
@@ -0,0 +1,24 @@
+func slv() {
+    guard let T = Int(readLine() ?? "") else { return }
+    
+    for _ in 0..<T {
+        guard let N = Int(readLine() ?? "") else { return }
+        
+        var n = N
+        var m = 0
+        var ans: [String] = []
+        
+        while n != 0 {
+            if n % 2 == 1 {
+                ans.append(String(m))
+            }
+            
+            m += 1
+            n /= 2
+        }
+        
+        print(ans.joined(separator: " "))
+    }
+}
+
+slv()
\ No newline at end of file