diff --git "a/khj20006/202511/19 PGM LV3 \352\260\200\354\236\245 \353\250\274 \353\205\270\353\223\234.md" "b/khj20006/202511/19 PGM LV3 \352\260\200\354\236\245 \353\250\274 \353\205\270\353\223\234.md"
new file mode 100644
index 00000000..c4054868
--- /dev/null
+++ "b/khj20006/202511/19 PGM LV3 \352\260\200\354\236\245 \353\250\274 \353\205\270\353\223\234.md"	
@@ -0,0 +1,34 @@
+```cpp
+#include <bits/stdc++.h>
+using namespace std;
+
+int solution(int n, vector<vector<int>> edge) {
+    const int INF = 123456;
+    
+    vector<vector<int>> graph(n+1);
+    for(auto e : edge) {
+        int a = e[0], b = e[1];
+        graph[a].push_back(b);
+        graph[b].push_back(a);
+    }
+    
+    queue<pair<int, int>> q;
+    vector<int> dist(n+1, INF);
+    q.emplace(1,0);
+    dist[1] = 0;
+    int mx = 0;
+    while(!q.empty()) {
+        auto [n,d] = q.front(); q.pop();
+        mx = max(mx, d);
+        for(int i:graph[n]) if(dist[i] == INF) {
+            dist[i] = d+1;
+            q.emplace(i, dist[i]);
+        }
+    }
+    
+    int ans = 0;
+    for(int i=1;i<=n;i++) if(dist[i] == mx) ans++;
+    
+    return ans;
+}
+```
\ No newline at end of file