diff --git a/06_mst/lee/10423.java b/06_mst/lee/10423.java
new file mode 100644
index 0000000..a60adba
--- /dev/null
+++ b/06_mst/lee/10423.java
@@ -0,0 +1,72 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+ static class Edge {
+ int to;
+ int weight;
+
+ public Edge(int to, int weight) {
+ this.to = to;
+ this.weight = weight;
+ }
+ }
+
+ static int N, M, K;
+ static ArrayList<Edge>[] powerStations;
+ static boolean[] visited;
+
+ public static void main(String[] args) throws Exception {
+ BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+ StringTokenizer st = new StringTokenizer(br.readLine());
+
+ N = Integer.parseInt(st.nextToken());
+ M = Integer.parseInt(st.nextToken());
+ K = Integer.parseInt(st.nextToken());
+
+ powerStations = new ArrayList[N + 1];
+ for (int i = 0; i <= N; i++) {
+ powerStations[i] = new ArrayList<>();
+ }
+ st = new StringTokenizer(br.readLine());
+ for (int i = 0; i < K; i++) {
+ int num = Integer.parseInt(st.nextToken());
+ powerStations[0].add(new Edge(num, 0));
+ powerStations[num].add(new Edge(0, 0));
+ }
+ for (int i = 1; i <= M; i++) {
+ st = new StringTokenizer(br.readLine());
+ int u = Integer.parseInt(st.nextToken());
+ int v = Integer.parseInt(st.nextToken());
+ int w = Integer.parseInt(st.nextToken());
+ powerStations[u].add(new Edge(v, w));
+ powerStations[v].add(new Edge(u, w));
+ }
+ System.out.println(prim());
+ }
+
+ private static int prim() {
+ int totalWeight = 0;
+ visited = new boolean[N + 1];
+ PriorityQueue<Edge> pq = new PriorityQueue<>((a, b) -> a.weight - b.weight);
+ pq.add(new Edge(1, 0));
+
+ while (!pq.isEmpty()) {
+ Edge current = pq.poll();
+ int node = current.to;
+ int weight = current.weight;
+
+ if (visited[node]) continue;
+
+ visited[node] = true;
+ totalWeight += weight;
+
+ for (Edge neighbor : powerStations[node]) {
+ if (!visited[neighbor.to]) {
+ pq.add(neighbor);
+ }
+ }
+ }
+ return totalWeight;
+ }
+}
\ No newline at end of file
diff --git a/06_mst/lee/1197.java b/06_mst/lee/1197.java
new file mode 100644
index 0000000..7f8312c
--- /dev/null
+++ b/06_mst/lee/1197.java
@@ -0,0 +1,68 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+ static class Edge {
+ int to;
+ int weight;
+
+ Edge(int to, int weight) {
+ this.to = to;
+ this.weight = weight;
+ }
+ }
+
+ private static int V, E;
+ private static List<Edge>[] edges;
+ private static boolean[] visited;
+
+ public static void main(String[] args) throws IOException {
+ BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+ StringTokenizer st = new StringTokenizer(br.readLine());
+
+ V = Integer.parseInt(st.nextToken());
+ E = Integer.parseInt(st.nextToken());
+
+ edges = new List[V + 1];
+ for (int i = 1; i <= V; i++) {
+ edges[i] = new ArrayList<>();
+ }
+ for (int i = 0; i < E; i++) {
+ st = new StringTokenizer(br.readLine());
+ int a = Integer.parseInt(st.nextToken());
+ int b = Integer.parseInt(st.nextToken());
+ int c = Integer.parseInt(st.nextToken());
+ edges[a].add(new Edge(b, c));
+ edges[b].add(new Edge(a, c));
+ }
+
+ System.out.println(prim(1));
+ }
+
+
+ private static int prim(int start) {
+ int totalWeight = 0;
+ visited = new boolean[V + 1];
+ PriorityQueue<Edge> pq = new PriorityQueue<>(Comparator.comparingInt(a -> a.weight));
+
+ pq.add(new Edge(1, 0));
+
+ while (!pq.isEmpty()) {
+ Edge current = pq.poll();
+ int node = current.to;
+ int weight = current.weight;
+
+ if (visited[node]) continue;
+
+ visited[node] = true;
+ totalWeight += weight;
+
+ for (Edge neighbor : edges[node]) {
+ if (!visited[neighbor.to]) {
+ pq.add(neighbor);
+ }
+ }
+ }
+ return totalWeight;
+ }
+}
diff --git a/06_mst/lee/16398.java b/06_mst/lee/16398.java
new file mode 100644
index 0000000..925ed55
--- /dev/null
+++ b/06_mst/lee/16398.java
@@ -0,0 +1,61 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+ static class Edge {
+ int to;
+ int weight;
+
+ Edge(int to, int weight) {
+ this.to = to;
+ this.weight = weight;
+ }
+ }
+
+ private static int N;
+ private static int[][] planet;
+ private static boolean[] inMST;
+
+ public static void main(String[] args) throws IOException {
+ BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+ N = Integer.parseInt(br.readLine());
+ planet = new int[N + 1][N + 1];
+ for (int i = 1; i <= N; i++) {
+ StringTokenizer st = new StringTokenizer(br.readLine());
+ for (int j = 1; j <= N; j++) {
+ planet[i][j] = Integer.parseInt(st.nextToken());
+ }
+ }
+
+ System.out.println(prim(1));
+ }
+
+
+ private static long prim(int start) {
+ long totalWeight = 0;
+ inMST = new boolean[N + 1];
+ PriorityQueue<Edge> pq = new PriorityQueue<>(Comparator.comparingInt(a -> a.weight));
+
+ pq.add(new Edge(1, 0));
+
+ while (!pq.isEmpty()) {
+ Edge current = pq.poll();
+ int node = current.to;
+ int weight = current.weight;
+
+ if (inMST[node]) continue;
+
+ inMST[node] = true;
+ totalWeight += weight;
+
+ for (int i = 1; i <= N; i++) {
+ if (!inMST[i]) {
+ pq.add(new Edge(i, planet[node][i]));
+ }
+ }
+ }
+ return totalWeight;
+ }
+}
diff --git a/06_mst/lee/1647.java b/06_mst/lee/1647.java
new file mode 100644
index 0000000..c64e845
--- /dev/null
+++ b/06_mst/lee/1647.java
@@ -0,0 +1,67 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+ static class Edge {
+ int to;
+ int weight;
+
+ public Edge(int to, int weight) {
+ this.to = to;
+ this.weight = weight;
+ }
+ }
+
+ static int N, M;
+ static ArrayList<Edge>[] cities;
+ private static boolean[] visited;
+
+ public static void main(String[] args) throws Exception {
+ BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+ StringTokenizer st = new StringTokenizer(br.readLine());
+
+ N = Integer.parseInt(st.nextToken());
+ M = Integer.parseInt(st.nextToken());
+ cities = new ArrayList[N + 1];
+ for (int i = 1; i <= N; i++) {
+ cities[i] = new ArrayList<>();
+ }
+ for (int i = 1; i <= M; i++) {
+ st = new StringTokenizer(br.readLine());
+ int a = Integer.parseInt(st.nextToken());
+ int b = Integer.parseInt(st.nextToken());
+ int c = Integer.parseInt(st.nextToken());
+ cities[a].add(new Edge(b, c));
+ cities[b].add(new Edge(a, c));
+ }
+ System.out.println(prim());
+ }
+
+ private static int prim() {
+ int totalWeight = 0;
+ int maxWeight = 0;
+ visited = new boolean[N + 1];
+ PriorityQueue<Edge> pq = new PriorityQueue<>((a, b) -> a.weight - b.weight);
+
+ pq.add(new Edge(1, 0));
+
+ while (!pq.isEmpty()) {
+ Edge current = pq.poll();
+ int node = current.to;
+ int weight = current.weight;
+
+ if (visited[node]) continue;
+
+ visited[node] = true;
+ totalWeight += weight;
+ maxWeight = Math.max(maxWeight, weight);
+
+ for (Edge neighbor : cities[node]) {
+ if (!visited[neighbor.to]) {
+ pq.add(neighbor);
+ }
+ }
+ }
+ return totalWeight - maxWeight;
+ }
+}
\ No newline at end of file
diff --git a/06_mst/lee/9372.java b/06_mst/lee/9372.java
new file mode 100644
index 0000000..34f11e8
--- /dev/null
+++ b/06_mst/lee/9372.java
@@ -0,0 +1,74 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+ private static int N, M;
+ private static boolean[] visited;
+ private static ArrayList<Integer>[] plane;
+
+ public static void main(String[] args) throws NumberFormatException, IOException {
+ BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+ StringBuilder sb = new StringBuilder();
+
+ int T = Integer.parseInt(br.readLine());
+
+ for (int tc = 1; tc <= T; tc++) {
+
+ StringTokenizer st = new StringTokenizer(br.readLine());
+ N = Integer.parseInt(st.nextToken());
+ M = Integer.parseInt(st.nextToken());
+
+ plane = new ArrayList[N + 1];
+ for (int i = 1; i <= N; i++) {
+ plane[i] = new ArrayList<Integer>();
+ }
+
+ for (int i = 1; i <= M; i++) {
+ st = new StringTokenizer(br.readLine());
+ int a = Integer.parseInt(st.nextToken());
+ int b = Integer.parseInt(st.nextToken());
+
+ plane[a].add(b);
+ plane[b].add(a);
+ }
+
+ visited = new boolean[N + 1];
+ sb.append(dfs(1)).append("\n"); // 방법 1
+ sb.append(bfs(1) - 1).append("\n"); // 방법 2
+ sb.append((N - 1)).append("\n"); // 방법 3 (최소 신장 트리의 성질 : 간선의 개수 == 정점의 개수 - 1)
+ }
+ System.out.println(sb.toString());
+ }
+
+ private static int dfs(int start) {
+ visited[start] = true;
+
+ int count = 0;
+ for (int destination : plane[start]) {
+ if (!visited[destination]) {
+ count += dfs(destination) + 1;
+ }
+ }
+ return count;
+ }
+
+ private static int bfs(int start) {
+ ArrayDeque<Integer> queue = new ArrayDeque<>();
+ queue.add(start);
+ visited[start] = true;
+
+ int count = 0;
+ while (!queue.isEmpty()) {
+ count++;
+ int current = queue.poll();
+
+ for (int destination : plane[current]) {
+ if (!visited[destination]) {
+ visited[destination] = true;
+ queue.add(destination);
+ }
+ }
+ }
+ return count;
+ }
+}