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OI-codes/BZOJ/1917/1917.cpp

85 lines
1.3 KiB
C++

#include <iostream>
#include <vector>
using std::cin;
using std::cout;
const char endl = '\n';
const int N = 50005;
int n, h[N], son[N], ans[N], res;
std::vector<int> g[N];
void dfs1(int u, int f) {
for (int v : g[u]) {
if (v == f) continue;
dfs1(v, u);
int x = std::min(h[u], h[v]);
h[u] -= x, h[v] -= x;
res += x * 2;
if (h[v]) son[u] = v;
}
}
void dfs2(int u, int f) {
ans[u] = res;
for (int v : g[u]) {
if (v == f) continue;
if (h[u]) {
h[u]--, res++;
dfs2(v, u);
h[u]++, res--;
} else if (son[v]) {
h[son[v]]--, res++;
dfs2(v, u);
h[son[v]]++, res--;
} else {
h[v]++, res--;
dfs2(v, u);
h[v]--, res++;
}
}
}
int main() {
std::ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> h[i];
}
for (int i = 1, x, y; i < n; i++) {
cin >> x >> y;
h[++x]--, h[++y]--;
g[x].emplace_back(y);
g[y].emplace_back(x);
res += 2;
}
dfs1(1, 0);
dfs2(1, 0);
for (int i = 1; i <= n; i++) {
cout << ans[i] << endl;
}
return 0;
}