Add a bunch of other problems.

Codeforces Round 1048 (Div. 1)/C1. Maple and Tree Beauty (Easy Version).cpp

@@ -91,46 +91,60 @@ void solve()
     int n, k;
     cin >> n >> k;
 
-    vi depth(n);
-    vi sums(n);
-    V<bool> leaf(n, true);
-
-    sums[0] = 1;
-
+    vvi graph(n);
     nrep(i, 1, n) {
-        int a;
-        cin >> a;
-        a--;
-
-        depth[i] = depth[a] + 1;
-        sums[depth[i]]++;
-        leaf[a] = false;
+        int j;
+        cin >> j;
+        graph[j - 1].push_back(i);
     }
 
-    int maxdepth = oo;
-    rep(i, n) {
-        if (leaf[i]) {
-            rmin(maxdepth, depth[i]);
+    vi sums;
+    int minimal = oo;
+
+    function<void(int, int)> calc = [&](int i, int d) {
+        if (d >= sums.size()) {
+            sums.emplace_back();
         }
-    }
 
-    vi dp(n + 1);
-    dp[0] = 1;
+        sums[d]++;
+        d++;
 
-    rep(i, maxdepth) {
-        for (int j = n; j >= sums[i]; j--) {
-            dp[j] |= dp[j - sums[i]];
-        }
-    }
-
-    rep(i, n + 1) {
-        if (dp[i] && i <= k && n - i <= n - k) {
-            cout << maxdepth + 1 << '\n';
+        if (graph[i].empty()) {
+            rmin(minimal, d);
             return;
         }
+
+        for (auto j : graph[i]) {
+            calc(j, d);
+        }
+    };
+
+    calc(0, 0);
+
+    V<V<int>> dp(sums.size() + 1, V<int>(k + 1, -1));
+    dp[0][k] = n - k;
+
+    int maximal = 0;
+
+    nrep(i, 1, minimal + 1) {
+        int cost = sums[i - 1];
+
+        rep(j, k + 1) {
+            if (j + cost <= k) {
+                rmax(dp[i][j], dp[i - 1][j + cost]);
+            }
+
+            if (dp[i - 1][j] >= cost) {
+                rmax(dp[i][j], dp[i - 1][j] - cost);
+            }
+
+            if (dp[i][j] >= 0) {
+                maximal = i;
+            }
+        }
     }
 
-    cout << maxdepth << '\n';
+    cout << maximal << '\n';
 }
 
 int main()