new file: P2014.cpp

P2014.cpp

@@ -0,0 +1,47 @@
+#include <bits/stdc++.h>
+#define int long long
+using namespace std;
+const int MAXN = 305;
+int n, m, s[MAXN];
+vector<int> g[MAXN];
+int dp[MAXN][MAXN];
+int sz[MAXN];
+void dfs(int u)
+{
+    sz[u] = 1;
+    for (int j = 0; j <= m + 1; ++j)
+        dp[u][j] = INT_MIN;
+    dp[u][1] = s[u];
+    for (int v : g[u])
+    {
+        dfs(v);
+        for (int i = sz[u]; i >= 1; --i)
+        {
+            if (dp[u][i] < 0)
+                continue;
+            for (int k = 1; k <= sz[v] && i + k <= m + 1; ++k)
+            {
+                if (dp[v][k] < 0)
+                    continue;
+                dp[u][i + k] = max(dp[u][i + k], dp[u][i] + dp[v][k]);
+            }
+        }
+        sz[u] += sz[v];
+    }
+}
+signed main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+    cin >> n >> m;
+    for (int i = 1; i <= n; ++i)
+    {
+        int fa;
+        cin >> fa >> s[i];
+        g[fa].push_back(i);
+    }
+    s[0] = 0;
+    dfs(0);
+    cout << dp[0][m + 1] << '\n';
+    return 0;
+}