python/TangDou/Topic/HuanGenDp/CF1324F.cpp

#include <bits/stdc++.h>
using namespace std;
const int N = 200010, M = N << 1;

// 链式前向星
int e[M], h[N], idx, w[M], ne[M];
void add(int a, int b, int c = 0) {
    e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx++;
}

int n, a[N], f1[N], f2[N];

void dfs1(int u, int fa) {
    if (a[u])
        f1[u] = 1;
    else
        f1[u] = -1;

    for (int i = h[u]; ~i; i = ne[i]) {
        int v = e[i];
        if (v == fa) continue;
        dfs1(v, u);
        f1[u] += max(f1[v], 0);
    }
}

void dfs2(int u, int fa) {
    for (int i = h[u]; ~i; i = ne[i]) {
        int v = e[i];
        if (v == fa) continue;
        f2[v] = max(f2[u] + f1[u] - max(f1[v], 0), 0);
        dfs2(v, u);
    }
}
int main() {
    // 初始化链式前向星
    memset(h, -1, sizeof h);
    cin >> n;

    for (int i = 1; i <= n; i++) cin >> a[i];

    for (int i = 1; i <= n - 1; i++) {
        int a, b;
        cin >> a >> b;
        add(a, b), add(b, a);
    }

    dfs1(1, 1);

    dfs2(1, 1);
    for (int i = 1; i <= n; i++) printf("%d ", f1[i] + f2[i]);

    return 0;
}