[nathan] 행성 터널 0309 java 풀이 실패 -> 답 보고 진행

nathan/java/src/main/java/org/example/mar/행성터널0309.java

@@ -0,0 +1,111 @@
+package org.example.mar;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+import java.util.PriorityQueue;
+import java.util.Queue;
+import java.util.StringTokenizer;
+
+public class 행성터널0309 {
+	int n;
+	int answer = Integer.MAX_VALUE;
+	List<Planet> xPlanets = new ArrayList<>();
+	List<Planet> yPlanets = new ArrayList<>();
+	List<Planet> zPlanets = new ArrayList<>();
+	Queue<Dist> pq = new PriorityQueue<>(Comparator.comparingInt(o -> o.val));
+
+	public static void main(String[] args) throws IOException {
+
+		행성터널0309 m = new 행성터널0309();
+		int solution = m.solution();
+		System.out.println(solution);
+	}
+	int solution() throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		n = Integer.parseInt(br.readLine());
+		StringTokenizer st;
+		int[] point = new int[3];
+		for (int i = 0; i < n; i++) {
+			st = new StringTokenizer(br.readLine());
+			for (int j = 0; j < 3; j++) {
+				point[j] = Integer.parseInt(st.nextToken());
+			}
+			xPlanets.add(new Planet(point[0], point[1], point[2], i));
+			yPlanets.add(new Planet(point[0], point[1], point[2], i));
+			zPlanets.add(new Planet(point[0], point[1], point[2], i));
+		}
+		xPlanets.sort(Comparator.comparingInt(o -> o.x));
+		yPlanets.sort(Comparator.comparingInt(o -> o.y));
+		zPlanets.sort(Comparator.comparingInt(o -> o.z));
+
+		for (int i = 0; i < n - 1; i++) {
+			pq.add(new Dist(xPlanets.get(i).idx, xPlanets.get(i + 1).idx,
+				Math.abs(xPlanets.get(i).x - xPlanets.get(i + 1).x)));
+			pq.add(new Dist(yPlanets.get(i).idx, yPlanets.get(i + 1).idx,
+				Math.abs(yPlanets.get(i).y - yPlanets.get(i + 1).y)));
+			pq.add(new Dist(zPlanets.get(i).idx, zPlanets.get(i + 1).idx,
+				Math.abs(zPlanets.get(i).z - zPlanets.get(i + 1).z)));
+		}
+		int ans = 0;
+		int[] parents = new int[n];
+		for (int i = 0; i < n; i++) {
+			parents[i] = i;
+		}
+		while (!pq.isEmpty()) {
+			Dist now = pq.poll();
+			if (find(now.a, parents) == find(now.b, parents)) {
+				continue;
+			}
+			union(now.a, now.b, parents);
+			ans += now.val;
+		}
+
+		return ans;
+	}
+
+	private int find(int a, int[] parents) {
+		if (parents[a] != a) {
+			parents[a] = find(parents[a], parents);
+		}
+		return parents[a];
+	}
+
+	private void union(int a, int b, int[] parents) {
+		if (find(a, parents) == find(b, parents)) {
+			return;
+		}
+		if (a < b) {
+			parents[find(b, parents)] = find(a, parents);
+		} else {
+			parents[find(a, parents)] = find(b, parents);
+		}
+	}
+
+	class Planet {
+		int x, y, z, idx;
+
+		public Planet(int x, int y, int z, int idx) {
+			this.x = x;
+			this.y = y;
+			this.z = z;
+			this.idx = idx;
+		}
+	}
+
+	class Dist {
+		int a;
+		int b;
+		int val;
+
+		public Dist(int a, int b, int val) {
+			this.a = a;
+			this.b = b;
+			this.val = val;
+		}
+	}
+
+}