2606 바이러스 / DFS

2021_03/BJ_2606.cpp

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+#include <iostream>
+#include <string.h>
+#include <vector>
+using namespace std;
+
+vector<int> map[101];
+bool check[101];
+int res = 0;
+
+void solution(int n) {
+    for (int i = 0; i < map[n].size(); i++) {
+        if (!check[map[n][i]]) {
+            check[map[n][i]] = true;
+            res++;
+            solution(map[n][i]);
+        }
+    }
+}
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    int size, n;
+    cin >> size >> n;
+    memset(check, false, sizeof(check));
+
+    for (int i = 0; i < n; i++) {
+        int a, b;
+        cin >> a >> b;
+        map[a].push_back(b);
+        map[b].push_back(a);
+    }
+
+    check[1] = true;
+    solution(1);
+    cout << res << endl;
+    return 0;
+}