add solutions

한민주/20250402/P1197.java

@@ -0,0 +1,88 @@
+package algorithm;
+
+// 메모리: 47884 KB, 시간: 464 ms
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.HashSet;
+import java.util.PriorityQueue;
+import java.util.StringTokenizer;
+
+class Edge implements Comparable<Edge> {
+	int from;
+	int to;
+	int weight;
+
+	public Edge(int from, int to, int weight) {
+		super();
+		this.from = from;
+		this.to = to;
+		this.weight = weight;
+	}
+
+	@Override
+	public int compareTo(Edge o) {
+		return this.weight - o.weight;
+	}
+
+}
+
+public class P1197 {
+	static int union[];
+
+	public static void main(String[] args) throws Exception {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		int v = Integer.parseInt(st.nextToken());
+		int e = Integer.parseInt(st.nextToken());
+		PriorityQueue<Edge> edges = new PriorityQueue<>();
+
+		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 w = Integer.parseInt(st.nextToken());
+
+			Edge newE = new Edge(a, b, w);
+			edges.add(newE);
+		}
+
+		int cnt = 0;
+		union = new int[v+1];
+		for (int i = 1; i < v + 1; i++) {
+			union[i] = i;
+		}
+		int ans = 0;
+		while (true) {
+			Edge now = edges.poll();
+//			System.out.println(now.from + " " + now.to);
+			if (find(now.from) == find(now.to))
+				continue;
+			union[union[now.from]] = union[now.to];
+			ans += now.weight;
+			cnt+=2;
+			if(cnt >= v) {
+				boolean noans = false;
+				for(int i = 2; i < v+1; i++) {
+					if(find(1) != find(i)) {
+						noans = true;
+						break;
+					}
+				}
+				if(!noans) {
+					break;
+				}
+			}
+		}
+
+		System.out.println(ans);
+	}
+
+	private static int find(int x) {
+		if (union[x] == x)
+			return x;
+		else {
+			return union[x] = find(union[x]);
+		}
+	}
+
+}

한민주/20250402/P1717.java

@@ -0,0 +1,51 @@
+package algorithm;
+
+// 메모리: 51376 KB, 시간: 352ms
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class P1717 {
+	static int u[];
+
+	public static void main(String[] args) throws Exception {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		int n = Integer.parseInt(st.nextToken());
+		int m = Integer.parseInt(st.nextToken());
+		StringBuilder sb = new StringBuilder();
+		u = new int[n + 1];
+		for (int i = 0; i <= n; i++) {
+			u[i] = i;
+		}
+		for (int i = 0; i < m; i++) {
+			st = new StringTokenizer(br.readLine());
+			int cal = Integer.parseInt(st.nextToken());
+			int a = Integer.parseInt(st.nextToken());
+			int b = Integer.parseInt(st.nextToken());
+			if (cal == 0) {
+				find(a);
+				u[find(b)] = u[a];
+			} else {
+				find(a);
+				find(b);
+				if (u[a] == u[b]) {
+					sb.append("yes");
+				} else {
+					sb.append("no");
+				}
+				sb.append("\n");
+			}
+		}
+		System.out.println(sb);
+	}
+
+	static int find(int x) {
+		if (x != u[x]) {
+			return u[x] = find(u[x]);
+		} else {
+			return x;
+		}
+	}
+
+}