Merge pull request #1552 from AlgorithmWithGod/khj20006

[20251130] BOJ / P5 / 즉흥 여행 (Easy) / 권혁준

Author: ShinHeeEul

khj20006/202511/30 BOJ P5 즉흥 여행 (Easy).md

@@ -0,0 +1,47 @@
+```cpp
+#include <bits/stdc++.h>
+using namespace std;
+
+int N, M;
+vector<vector<int>> G(200001), R(200001);
+bitset<200001> vis;
+int last, cnt = 0;
+
+void dfs1(int n) {
+	for (int i : G[n]) if (!vis[i]) {
+		vis[i] = 1;
+		dfs1(i);
+	}
+	last = n;
+}
+
+void dfs2(int n) {
+	cnt++;
+	for (int i : R[n]) if (!vis[i]) {
+		vis[i] = 1;
+		dfs2(i);
+	}
+}
+
+int main() {
+	cin.tie(0)->sync_with_stdio(0);
+
+	cin >> N >> M;
+	for (int a, b; M--;) {
+		cin >> a >> b;
+		G[a].push_back(b);
+		R[b].push_back(a);
+	}
+
+	for (int i = 1; i <= N; i++) if (!vis[i]) {
+		vis[i] = 1;
+		dfs1(i);
+	}
+
+	vis.reset();
+	vis[last] = 1;
+	dfs2(last);
+	cout << (cnt == N ? "Yes" : "No");
+
+}
+```