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class Solution {
public:
vector<vector<int>> g;
vector<int> price;
int ans = 0;
int dfs(int u, int p, int &mx, int &mn) {
mx = mn = price[u];
for (int v : g[u]) {
if (v == p) continue;
int cmx, cmn;
dfs(v, u, cmx, cmn);
mx = max(mx, price[u] + cmx);
mn = min(mn, price[u] + cmn);
}
return 0;
}
void reroot(int u, int p, int upmx, int upmn) {
int mx = price[u], mn = price[u];
vector<pair<int,int>> child;
for (int v : g[u]) {
if (v == p) continue;
int cmx, cmn;
dfs(v, u, cmx, cmn);
child.push_back({cmx, cmn});
mx = max(mx, price[u] + cmx);
mn = min(mn, price[u] + cmn);
}
mx = max(mx, price[u] + upmx);
mn = min(mn, price[u] + upmn);
ans = max(ans, mx - mn);
int idx = 0;
for (int v : g[u]) {
if (v == p) continue;
int nmx = price[u], nmn = price[u];
for (int j = 0; j < child.size(); ++j) {
if (j == idx) continue;
nmx = max(nmx, price[u] + child[j].first);
nmn = min(nmn, price[u] + child[j].second);
}
nmx = max(nmx, price[u] + upmx);
nmn = min(nmn, price[u] + upmn);
reroot(v, u, nmx - price[v], nmn - price[v]);
idx++;
}
}
int maxOutput(int n, vector<vector<int>>& edges, vector<int>& price_) {
g.assign(n, {});
price = price_;
for (auto &e : edges) {
g[e[0]].push_back(e[1]);
g[e[1]].push_back(e[0]);
}
int mx, mn;
dfs(0, -1, mx, mn);
reroot(0, -1, 0, 0);
return ans;
}
};
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