Submission #74772537

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;

#define int long long
//#define float long double

using uint = unsigned;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using pff = pair<float,float>;
using pdd = pair<ld,ld>;

#define endl '\n'
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define pf push_front
#define fi first
#define se second

const ld PI = 3.14159265358979323846;
const ld E = 2.71828182845904523536;
const int MOD = 998244353;

int n;
vector<vector<int>> adj;
vector<int> w;
vector<int> s;
int ans = 0;

void dfs1(int p,int fa)
{
    s[p] = w[p];
    if(w[p] != 0)
        return;
    for(auto i : adj[p])
    {
        if(i == fa)
            continue;
        dfs1(i,p);
        s[p] += s[i];
    }
}

void dfs2(int p,int fa)
{
    int mx = -1;
    int mn = LLONG_MAX;
    if(w[p] != 0)
    {
        ans = max(ans,0ll);
        return;
    }
    for(auto i : adj[p])
    {
        if(i == fa)
            continue;
        mx = max(mx,s[i]);
        mn = min(mn,s[i]);
        dfs2(i,p);
    }
    ans = max(ans,mx-mn);
}

void solve()
{
    ans = 0;
    cin >> n;
    adj.resize(n+1);
    w.resize(n+1);
    s.resize(n+1);
    for(int i = 2;i <= n;i++)
    {
        int p;
        cin >> p;
        adj[i].pb(p);
        adj[p].pb(i);
    }
    for(int i = 1;i <= n;i++)
    {
        cin >> w[i];
    }
    dfs1(1,0);
    dfs2(1,0);
    cout << ans << endl;
}

signed main()
{
    std::cin.tie(nullptr);std::ios::sync_with_stdio(false);
    
    int tt = 1;
    //cin >> tt;
    while(tt--)
    {
        solve();
    }

    return 0;
}

Submission Info

Judge Result