Submission #1247331

#	Time	Username	Problem	Language	Result	Execution time	Memory
1247331		hainam2k9	Arboras (RMI20_arboras)	C++20	55 / 100	5093 ms	15124 KiB

arboras

#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
#define mp make_pair
using namespace std;
const int MOD = 1e9+7, MAXN = 1e5+5;
const string NAME = "";
int n,q,par[MAXN],rs=0;
int sz[MAXN],head[MAXN],pos[MAXN],curpos=0;
ull edge[MAXN];
vector<pair<int,int>> adj[MAXN];
pair<pair<int,ull>,pair<int,ull>> dp[MAXN];
inline void add(int& a, int b){
    a+=b;
    if(a>=MOD) a-=MOD;
}
inline void sub(int& a, int b){
    a-=b;
    if(a<0) a+=MOD;
}
inline void maximize(pair<pair<int,ull>,pair<int,ull>>& p, pair<int,ull> x){
    if(x.fi==p.fi.fi) p.fi.se=x.se;
    else if(x.se==p.se.fi){
        p.se.se=x.se;
        if(p.fi.se<p.se.se) swap(p.fi,p.se);
    }
    else if(x.se>p.fi.se) swap(p.fi,p.se), p.fi=x;
    else if(x.se>p.se.se) p.se=x;
}
void dfs(int u){
    sz[u]=1;
    for(pair<int,int>& e : adj[u]){
        if(e.fi==par[u]) continue;
        dfs(e.fi);
        sz[u]+=sz[e.fi];
    }
}
void HLD(int u, int curhead){
    head[u]=curhead, pos[u]=++curpos;
    int heavy=0;
    for(pair<int,int>& e : adj[u])
        if(e.fi!=par[u]&&sz[e.fi]>sz[heavy]) heavy=e.fi;
    if(heavy!=0) HLD(heavy,curhead);
    for(pair<int,int>& e : adj[u])
        if(e.fi!=par[u]&&e.fi!=heavy) HLD(e.fi,e.fi);
    for(pair<int,int>& e : adj[u])
        if(e.fi!=par[u]) edge[pos[e.fi]]=e.se, maximize(dp[pos[u]],{pos[e.fi],dp[pos[e.fi]].fi.se+e.se});
    add(rs,(dp[pos[u]].fi.se+dp[pos[u]].se.se)%MOD);
}
inline void update(int x, pair<int,ull> val){
    while(x>0){
        for(int i=pos[x], lim=pos[head[x]]; i>=lim; --i){
            if(dp[i].se.se>val.se) return;
            sub(rs,(dp[i].fi.se+dp[i].se.se)%MOD);
            maximize(dp[i],val);
            add(rs,(dp[i].fi.se+dp[i].se.se)%MOD);
            if(val.se<dp[i].fi.se) return;
            val.fi=i, val.se+=edge[i];
        }
        x=par[head[x]];
    }
}
int main()
{
    tt;
    if(fopen((NAME + ".INP").c_str(), "r")) fo;
    cin >> n;
    for(int i = 2; i<=n; ++i)
        cin >> par[i], ++par[i];
    for(int i = 2; i<=n; ++i){
        int dist;
        cin >> dist;
        adj[i].pb(par[i],dist), adj[par[i]].pb(i,dist);
    }
    dfs(1);
    HLD(1,1);
    cout << rs << "\n";
    cin >> q;
    while(q--){
        int x,y;
        cin >> x >> y;
        ++x, edge[pos[x]]+=y;
        if(dp[pos[x]].fi.se+edge[pos[x]]>dp[pos[par[x]]].se.se) update(par[x],{pos[x],dp[pos[x]].fi.se+edge[pos[x]]});
        cout << rs << "\n";
    }
}

Compilation message (stderr)

arboras.cpp: In function 'int main()':
arboras.cpp:4:19: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    4 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arboras.cpp:81:45: note: in expansion of macro 'fo'
   81 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~
arboras.cpp:4:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    4 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |                                                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arboras.cpp:81:45: note: in expansion of macro 'fo'
   81 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~

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