boj 6497 전력난

Author: emost22

최소 스패닝 트리/Kruskal/6497.cpp

@@ -0,0 +1,85 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#define MAX 200001
+using namespace std;
+
+typedef struct Node {
+	int u, v, w;
+}Node;
+
+Node list[MAX];
+int parent[MAX];
+int N, M, sum;
+
+bool cmp(Node a, Node b) {
+	return a.w < b.w;
+}
+
+void init() {
+	for (int i = 0; i < N; i++) {
+		parent[i] = i;
+	}
+}
+
+int find(int v) {
+	if (parent[v] == v) return v;
+	return parent[v] = find(parent[v]);
+}
+
+bool unionNode(int u, int v) {
+	u = find(u);
+	v = find(v);
+
+	if (parent[u] != parent[v]) {
+		parent[v] = parent[u];
+		return true;
+	}
+
+	return false;
+}
+
+void func() {
+	init();
+
+	sort(list, list + M, cmp);
+
+	int ret = 0;
+	int cnt = 0;
+	for (int i = 0; i < M; i++) {
+		int u = list[i].u;
+		int v = list[i].v;
+
+		if (unionNode(u, v)) {
+			ret += list[i].w;
+			cnt++;
+		}
+
+		if (cnt == N - 1) break;
+	}
+
+	cout << sum - ret << '\n';
+}
+
+void input() {
+	cin >> N >> M;
+	if (!N && !M) exit(0);
+
+	sum = 0;
+	for (int i = 0; i < M; i++) {
+		cin >> list[i].u >> list[i].v >> list[i].w;
+		sum += list[i].w;
+	}
+}
+
+int main() {
+	cin.tie(NULL); cout.tie(NULL);
+	ios::sync_with_stdio(false);
+
+	while (1) {
+		input();
+		func();
+	}
+
+	return 0;
+}