#include <bits/stdc++.h> using namespace std; #include "friend.h" int colour[100001], dp[2][100001], c[100001]; vector<int> graph[100001]; void dfs(int node) { dp[0][node] = c[node]; for (int i : graph[node]) { dfs(i); if (!colour[i]) dp[1][node] += dp[0][i], dp[0][node] += dp[1][i]; else dp[0][node] += dp[0][i], dp[1][node] += dp[1][i]; } int curr = dp[1][node]; dp[0][node] = max(dp[0][node], curr); for (int i : graph[node]) { if (!colour[i]) curr += dp[1][i] - dp[0][i]; else curr += dp[0][i] - dp[1][i]; dp[0][node] = max(dp[0][node], curr); } } int findSample(int n, int confidence[], int host[], int protocol[]) { if (protocol[1] == 2) return *max_element(confidence, confidence + n); c[0] = confidence[0]; for (int i = 1; i < n; i++) { c[i] = confidence[i]; colour[i] = protocol[i]; graph[host[i]].push_back(i); } dfs(0); return *max_element(dp[0], dp[0] + 2); }