modified: 30.cpp

30.cpp

@@ -1 +1,46 @@
-// 115
+// 115 not finished
+#include <bits/stdc++.h>
+using namespace std;
+int n;
+int a[1005];
+int fa[1005];
+int dt[1005];
+int root;
+vector<int> chi[1005];
+bool ran[1005];
+int ans, T;
+void dfs(int now) // 染色到dt[now]
+{
+    if (dt[now] == root)
+    {
+        ran[now] = 1, ans += (T++) * a[dt[now]];
+        return;
+    }
+    if (!ran[fa[dt[now]]])
+        dfs(fa[dt[now]]);
+    ran[now] = 1, ans += (T++) * a[dt[now]];
+}
+int main()
+{
+    scanf("%d", &n);
+    for (int i = 1; i <= n; ++i)
+        scanf("%d", &a[i]), dt[i] = i;
+    sort(dt + 1, dt + n + 1, [](int x, int y)
+         { return a[x] < a[y]; });
+    for (int u, v, i = 1; i < n; ++i)
+        scanf("%d%d", &u, &v),
+            fa[v] = u, chi[u].push_back(v);
+    for (int i = 1; i <= n; ++i)
+    {
+        if (fa[i] == i)
+        {
+            root = i;
+            break;
+        }
+    }
+    for (int i = 1; i <= n; ++i)
+    {
+        dfs(i);
+    }
+    printf("%d\n", ans);
+}