P1352 没有上司的舞会

R41231597

problem/P1352/P1352.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+/* Template: 树形 DP */
+vector<int> son[6005];
+int         n, l, k, f[6005][2], h[6005];
+bool        v[6005];
+
+void dp(int x) {
+    int y;
+    f[x][0] = 0;
+    f[x][1] = h[x];
+    for (int i = 0; i < son[x].size(); i++) {
+        y = son[x][i];
+        dp(y);
+        f[x][0] += max(f[y][0], f[y][1]);
+        f[x][1] += f[y][0];
+    }
+}
+
+int main() {
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> h[i];
+    }
+    for (int i = 1; i < n; i++) {
+        cin >> l >> k;
+        v[l] = 1;
+        son[k].push_back(l);
+    }
+    int root;
+    for (int i = 1; i <= n; i++) {
+        if (!v[i]) {
+            root = i;
+            break;
+        }
+    }
+    dp(root);
+    cout << max(f[root][0], f[root][1]) << endl;
+    return 0;
+}