[20250618] BOJ / G3 / 나만 안되는 연애 / 김수연

Author: suyeun84

suyeun84/202506/18 BOJ G3 나만 안되는 연애.md

@@ -0,0 +1,70 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class boj14621 {
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static StringTokenizer st;
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static int nextInt() {return Integer.parseInt(st.nextToken());}
+	
+	static int N, M, answer;
+	static char[] gender;
+	static Road[] roads;
+	static int[] parent;
+	public static void main(String[] args) throws Exception {
+		nextLine();
+		N = nextInt();
+		M = nextInt();
+		answer = 0;
+		nextLine();
+		gender = new char[N+1];
+		roads = new Road[M];
+		parent = new int[N+1];
+		for (int i = 1; i <= N; i++) {
+			gender[i] = st.nextToken().charAt(0);
+			parent[i] = i;
+		}
+		for (int i = 0; i < M; i++) {
+			nextLine();
+			int u = nextInt();
+			int v = nextInt();
+			int d = nextInt();
+			roads[i] = new Road(u, v, d);
+		}
+		Arrays.sort(roads, (o1, o2) -> o1.d-o2.d);
+		int cnt = 0;
+		for (int i = 0; i < M; i++) {
+			if (gender[roads[i].s] == gender[roads[i].e]) continue;
+			if (find(roads[i].s) == find(roads[i].e)) continue;
+			answer += roads[i].d;
+			union(roads[i].s, roads[i].e);
+			cnt++;
+		}
+		if (cnt != N-1) System.out.println(-1);
+		else System.out.println(answer);
+	}
+	
+	static int find(int x) {
+		if (x == parent[x]) return x;
+		return parent[x] = find(parent[x]);
+	}
+	
+	static void union(int x, int y) {
+		x = parent[x];
+		y = parent[y];
+		
+		if (x<y) parent[y] = x;
+		else parent[x] = y;
+	}
+	
+	static class Road {
+		int s, e, d;
+		public Road(int s, int e, int d) {
+			this.s = s;
+			this.e = e;
+			this.d = d;
+		}
+	}
+}
+```