boj 24391 귀찮은 해강이

Author: emost22

분리 집합/24391.cpp

@@ -0,0 +1,59 @@
+#include <iostream>
+#define MAX 100001
+using namespace std;
+
+int parent[MAX];
+int N, M;
+
+int find(int v) {
+	if (parent[v] == v) return v;
+	return parent[v] = find(parent[v]);
+}
+
+void unionNode(int u, int v) {
+	u = find(u);
+	v = find(v);
+	if (parent[u] != parent[v]) parent[v] = u;
+}
+
+void func() {
+	int pre = -1;
+	int ret = 0;
+	int x;
+	while (N--) {
+		cin >> x;
+		int p = find(x);
+		if (pre != p) {
+			if (pre != -1) ret++;
+			pre = p;
+		}
+	}
+
+	cout << ret << '\n';
+}
+
+void init() {
+	for (int i = 1; i <= N; i++) {
+		parent[i] = i;
+	}
+}
+
+void input() {
+	int u, v;
+	cin >> N >> M;
+	init();
+	while (M--) {
+		cin >> u >> v;
+		unionNode(u, v);
+	}
+}
+
+int main() {
+	cin.tie(NULL); cout.tie(NULL);
+	ios::sync_with_stdio(false);
+
+	input();
+	func();
+
+	return 0;
+}