new file: P10109.cpp

P10109.cpp

@@ -0,0 +1,64 @@
+#include <bits/stdc++.h>
+using namespace std;
+int n;
+int fa[305];
+vector<int> so[305];
+int a[305];
+bool vis[305];
+int de[305];
+void dfs(int now, int dep)
+{
+    vis[now] = 1;
+    de[now] = dep;
+    for (int i : so[now])
+    {
+        if (!vis[i])
+            dfs(i, dep + 1);
+    }
+}
+int l(int a, int b)
+{
+    while (de[a] > de[b])
+        a = fa[a];
+    while (de[a] < de[b])
+        b = fa[b];
+    while (a != b)
+        a = fa[a], b = fa[b];
+    return a;
+}
+int main()
+{
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+    cin >> n;
+    for (int i = 1; i < n; ++i)
+    {
+        cin >> fa[i];
+        so[fa[i]].push_back(i);
+    }
+    dfs(0, 0);
+    int q;
+    cin >> q;
+    while (q--)
+    {
+        int m;
+        cin >> m;
+        for (int i = 1; i <= m; ++i)
+        {
+            cin >> a[i];
+        }
+        int lca = a[1];
+        for (int i = 2; i <= m; ++i)
+        {
+            lca = l(lca, a[i]);
+        }
+        int mx = lca;
+        while (lca != 0)
+        {
+            lca = fa[lca];
+            mx = max(lca, mx);
+        }
+        cout << mx << endl;
+    }
+    return 0;
+}