P2097 资料分发1

R40129919

problem/P2097/P2097.cpp

@@ -0,0 +1,34 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+vector<int> l[100010];
+int         n, m, f, s, ans, pd[100010];
+
+void dfs(int x) {
+    for (int y = 0; y < l[x].size(); y++) {
+        if (!pd[l[x][y]]) {
+            pd[l[x][y]] = 1;
+            dfs(l[x][y]);
+        }
+    }
+}
+
+int main() {
+    int p, q;
+    cin >> n >> m;
+    for (int i = 1; i <= m; i++) {
+        cin >> p >> q;
+        l[p].push_back(q);
+        l[q].push_back(p);
+    }
+    for (int i = 1; i <= n; i++) {
+        if (!pd[i]) {
+            ans++;
+            pd[i] = 1;
+            dfs(i);
+        }
+    }
+    cout << ans << endl;
+    return 0;
+}