From 87f9e1d85decfbcf98cfefcc97d2cfccf18bffda Mon Sep 17 00:00:00 2001
From: Ren Baoshuo <i@baoshuo.ren>
Date: Thu, 3 Dec 2020 17:38:27 +0800
Subject: [PATCH] =?UTF-8?q?P1536=20=E6=9D=91=E6=9D=91=E9=80=9A?=
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R43106178
---
 problem/P1536/P1536.cpp | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 problem/P1536/P1536.cpp

diff --git a/problem/P1536/P1536.cpp b/problem/P1536/P1536.cpp
new file mode 100644
index 00000000..83c9bd84
--- /dev/null
+++ b/problem/P1536/P1536.cpp
@@ -0,0 +1,33 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, m, x, y, ans, f[100005];
+
+int find(int x) {
+    if (f[x] == x) return x;
+    return f[x] = find(f[x]);
+}
+
+void unity(int x, int y) {
+    f[find(x)] = find(y);
+}
+
+int main() {
+    while (cin >> n, n) {
+        ans = 0;
+        cin >> m;
+        for (int i = 1; i <= n; i++) {
+            f[i] = i;
+        }
+        for (int i = 1; i <= m; i++) {
+            cin >> x >> y;
+            unity(x, y);
+        }
+        for (int i = 1; i <= n; i++) {
+            if (find(i) == i) ans++;
+        }
+        cout << --ans << endl;
+    }
+    return 0;
+}