2023-12-08

tasks/online_judge/baekjoon/cpp/24391.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+#define MAX 100'000
+using namespace std;
+
+int parents[MAX];
+
+int find(int n) {
+  if (parents[n] == n) return n;
+  return parents[n] = find(parents[n]);
+}
+
+void merge(int a, int b) {
+  int pa = find(a), pb = find(b);
+  if (pa > pb) {
+    parents[pa] = pb;
+    parents[a] = pb;
+  } else {
+    parents[pb] = pa;
+    parents[b] = pa;
+  }
+}
+
+int main() {
+  int n, m;
+  cin >> n >> m;
+  for (int i = 0; i < n + 1; i++) parents[i] = i;
+  int a, b;
+  for (int i = 0; i < m; i++) {
+    cin >> a >> b;
+    merge(a, b);
+  }
+  int count = 0;
+  int prev, now;
+  cin >> prev;
+  for (int i = 1; i < n; i++) {
+    cin >> now;
+    if (find(prev) != find(now)) count++;
+    prev = now;
+  }
+  cout << count << endl;
+  return 0;
+}