baekjoon/gold4/q1922_network_connection(네트워크연결)

baekjoon/java/src/gold4/Q1922_ConnectionOfNetwork.java

@@ -0,0 +1,66 @@
+package gold4;
+
+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.StringTokenizer;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+// https://www.acmicpc.net/problem/1922
+public class Q1922_ConnectionOfNetwork {
+    private static int[] parents;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int n = Integer.parseInt(br.readLine());
+        parents = new int[n + 1];
+        for (int i = 1; i <= n; i++) {
+            parents[i] = i;
+        }
+        List<List<Integer>> connections = new ArrayList<>();
+        int m = Integer.parseInt(br.readLine());
+        for (int i = 0; i < m; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+            int c = Integer.parseInt(st.nextToken());
+            connections.add(Stream.of(c, a, b).collect(Collectors.toList()));
+        }
+
+        connections.sort(Comparator.comparingInt(conn -> conn.get(0)));
+        int total = 0;
+        for (List<Integer> connection : connections) {
+            int x = connection.get(1);
+            int y = connection.get(2);
+            if (findParent(x) != findParent(y)) {
+                union(x, y);
+                total += connection.get(0);
+            }
+        }
+        System.out.println(total);
+    }
+
+    private static int findParent(int x) {
+        if (parents[x] != x) {
+            parents[x] = findParent(parents[x]);
+        }
+        return parents[x];
+    }
+
+    private static void union(int x, int y) {
+        x = findParent(x);
+        y = findParent(y);
+        if (x == y) {
+            return;
+        }
+        if (x < y) {
+            parents[y] = x;
+            return;
+        }
+        parents[x] = y;
+    }
+}

baekjoon/python/gold4/q1922_network_connection.py

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+# https://www.acmicpc.net/problem/1922
+def solution():
+    global parent
+    n = int(input())
+    parent = [i for i in range(n+1)]
+    connections = []
+    m = int(input())
+    for _ in range(m):
+        a, b, c = map(int, input().split())
+        connections.append((c, a, b))
+    connections.sort()
+    total = 0
+    for conn in connections:
+        c, a, b = conn
+        if find_p(a) != find_p(b):
+            union(a, b)
+            total += c
+    return total
+
+def find_p(x):
+    if parent[x] != x:
+        parent[x] = find_p(parent[x])
+    return parent[x]
+
+def union(x, y):
+    x = find_p(x)
+    y = find_p(y)
+    if x == y :
+        return
+    if x < y :
+        parent[y] = x
+    else:
+        parent[x] = y
+
+print(solution())