From 34b4809d7bdf20725d97e8d5da22bb1c7a573b15 Mon Sep 17 00:00:00 2001 From: oncsr Date: Sun, 30 Nov 2025 23:46:25 +0900 Subject: [PATCH] =?UTF-8?q?[20251130]=20BOJ=20/=20P5=20/=20=EC=A6=89?= =?UTF-8?q?=ED=9D=A5=20=EC=97=AC=ED=96=89=20(Easy)=20/=20=EA=B6=8C?= =?UTF-8?q?=ED=98=81=EC=A4=80?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...35\245 \354\227\254\355\226\211 (Easy).md" | 47 +++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 "khj20006/202511/30 BOJ P5 \354\246\211\355\235\245 \354\227\254\355\226\211 (Easy).md" diff --git "a/khj20006/202511/30 BOJ P5 \354\246\211\355\235\245 \354\227\254\355\226\211 (Easy).md" "b/khj20006/202511/30 BOJ P5 \354\246\211\355\235\245 \354\227\254\355\226\211 (Easy).md" new file mode 100644 index 00000000..f468354b --- /dev/null +++ "b/khj20006/202511/30 BOJ P5 \354\246\211\355\235\245 \354\227\254\355\226\211 (Easy).md" @@ -0,0 +1,47 @@ +```cpp +#include +using namespace std; + +int N, M; +vector> 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"); + +} +```