Submission #943146

#	Time	Username	Problem	Language	Result	Execution time	Memory
943146		Foolestboy	Arboras (RMI20_arboras)	C++14	0 / 100	5051 ms	10372 KiB

arboras

#include <bits/stdc++.h>

#define SQR(x)    (1LL * ((x) * (x)))
#define MASK(i)   (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define fi        first
#define se        second
#define pb        push_back
#define all(x)    x.begin(), x.end()
#define rall(x)   x.rbegin(), x.rend()
#define sz(s)     (int)s.size()
#define prev      __prev
#define next      __next
#define left      __left
#define right     __right

#define mp make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define vi vector<int>
#define vll vector<ll>

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef unsigned int ui;

using namespace std;

const int mod = 1e9 + 7;
const int INF = 1e9 + 7;
const ll INFLL = (ll)2e18 + 7LL;
const ld PI = acos(-1);

const int dx[] = {1, -1, 0, 0, -1, 1, 1, -1};
const int dy[] = {0, 0, 1, -1, -1, -1, 1, 1};

template<class BUI, class TRONG>
    bool minimize(BUI &x, const TRONG y){
        if(x > y){
            x = y;
            return true;
        } else return false;
    }
template<class BUI, class TRONG>
    bool maximize(BUI &x, const TRONG y){
        if(x < y){
            x = y;
            return true;
        } else return false;
    }

/* Author : Bui Nguyen Duc Trong, Luong Van Chanh High School for the gifted*/
/* Template is copied by Trong */

                           /** Losing in Provincial Contests **/
                                    /** TRYING HARDER**/
                                   /**      ORZ     **/

/* -----------------[ MAIN CODE GOES HERE ]----------------- */

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int N = 1e5 + 10;
const int MOD = (int)1e9 + 7;

int n;
vector<int> adj[N];
ll d[N];
ll f[N], g[N];

void dfs(int u){
    pll z(0, 0);
    for(int v : adj[u]){
        dfs(v);
        if(z.fi == 0) z.fi = f[v] + d[v];
        else{
            if(z.se == 0){
                z.se = f[v] + d[v];
                if(z.fi < z.se) swap(z.fi, z.se);
            }
            else{
                if(!maximize(z.fi, f[v] + d[v])) maximize(z.se, f[v] + d[v]);
            }
        }
    }
    f[u] = z.fi;
    g[u] = z.fi + z.se;
}

int getAns(){
    dfs(0);
    ll ans = 0;
    for(int i = 0; i < n; i++) ans = (ans + g[i]) % MOD;
    return ans;
}

void solve(){
    cin >> n;
    for(int i = 1; i < n; i++){
        int p; cin >> p;
        adj[p].push_back(i);
    }
    for(int i = 1; i < n; i++) cin >> d[i];
    cout << getAns() << '\n';
    int q;
    cin >> q;
    while(q--){
        int v, k; cin >> v >> k;
        d[v] += k;
        dfs(0);
        cout << getAns() << '\n';
    }
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    const bool multitest = 0;
    int tt = 1; if(multitest) cin >> tt;

    while( tt-- ){

        solve();

    }

    return 0;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 13
• Subtask 3: 0 / 31
• Subtask 4: 0 / 45