Submission #1244136

#	Time	Username	Problem	Language	Result	Execution time	Memory
1244136		cpdreamer	봉쇄 시간 (IOI23_closing)	C++17	8 / 100	351 ms	50944 KiB

closing

#include "closing.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;
const long long INF = 1e18+1;
typedef long long ll;
const ll MOD =  1e9+7;
#define F first
#define P pair
#define S second
#define pb push_back
#define all(v) v.begin(), v.end()
typedef tree<int,null_type,less<int>,rb_tree_tag,
tree_order_statistics_node_update> indexed_set;
void file() {
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
}
vector<P<int,ll>>adj[(int)2e5+1];
bool b[(int)2e5+1];
ll d1[(int)2e5+1];
ll d2[(int)2e5+1];
void dfs1(int n,int p,int y) {
    if (n==y) {
        b[n]=true;
        return;
    }
    for (auto [u,w]:adj[n]) {
        if (u==p)continue;
        dfs1(u,n,y);
        b[n]|=b[u];
    }
}
void dfs2(int n,int p) {
    for (auto [u,w]:adj[n]) {
        if (u==p)continue;
        d1[u]=d1[n]+w;
        dfs2(u,n);
    }
}
void dfs3(int n,int p) {
    for (auto [u,w]:adj[n]) {
        if (u==p)continue;
        d2[u]=d2[n]+w;
        dfs3(u,n);
    }
}
int max_score(int N, int X, int Y, long long K,
              std::vector<int> U, std::vector<int> V, std::vector<int> W)
{
    for (int i=0;i<=N;i++) {
        adj[i].clear();
        b[i]=false;
    }
    d1[X]=0;d2[Y]=0;
    for (int i=0;i<N-1;i++) {
        adj[U[i]].pb({V[i],W[i]});
        adj[V[i]].pb({U[i],W[i]});
    }
    dfs1(X,-1,Y);
    dfs2(X,-1);
    dfs3(Y,-1);
    for (int i=0;i<N;i++) {
        if (d1[i]>d2[i])swap(d1[i],d2[i]);
    }
    ll v[N];
    for (int i=0;i<N;i++) {
        v[i]=d1[i];
    }
    sort(v,v+N);
    ll z=0;
    int ans=0;
    for (int i=0;i<N;i++) {
        z+=v[i];
        if (z<=K)ans++;
    }
    multiset<P<ll,int>>st1,st2;
    int c=0,ans1=0;
    ll cst=0;
    for (int i=0;i<N;i++) {
        if (b[i]) {
            cst+=d1[i];
            c++;
        }
    }
    if (cst<=K) {
        ans1=c;
    }
    for (int i=0;i<N;i++) {
        if (b[i]) {
            st1.insert({d2[i]-d1[i],i});
        }
        else {
            st1.insert({d1[i],i});
            st2.insert({d2[i],i});
        }
    }
    while (true) {
        if (cst<=K) {
            ans1=c;
        }
        if (st1.empty() && st2.empty()) {
            break;
        }
        bool f1=false;
        bool f2=false;
        bool f3=false;
        if (st2.empty()) {
            f3=true;
        }
        else {
            if (st1.size()==1) {
                f3=true;
            }
            else {
                if (min(st1.begin()->F+next(st1.begin())->F,st2.begin()->F)+cst>K) {
                    f3=true;
                }
                else {
                    if (st1.begin()->F+next(st1.begin())->F>st2.begin()->F) {
                        f2=true;
                    }
                    else
                        f1=true;
                }
            }
        }
        if (f1) {
            auto it1=st1.begin();
            auto it2=next(st1.begin());
            auto p1=*st1.begin();
            auto p2=*next(st1.begin());
            cst+=it1->F+it2->F;
            c+=2;
            auto g=st2.find({d2[it1->S],it1->S});
            if (g!=st2.end()) {
                st2.erase(g);
            }
            g=st2.find({d2[it2->S],it2->S});
            if (g!=st2.end()) {
                st2.erase(g);
            }
            st1.erase(it1);
            st1.erase(it2);
            if (!b[p1.S]) {
                st1.insert({d2[p1.S]-d1[p1.S],p1.S});
            }
            if (!b[p2.S]) {
                st1.insert({d2[p2.S]-d1[p2.S],p2.S});
            }

            b[p1.S]=true;
            b[p2.S]=true;
        }
        if (f2){
            auto it=st2.begin();
            cst+=it->F;
            c+=2;
            auto g=st1.find({d1[it->S],it->S});
            st1.erase(g);
            st2.erase(it);
        }
        if (f3) {
            auto it=st1.begin();
            auto p=*st1.begin();
            cst+=it->F;
            c++;
            break;
        }
    }
    if (cst<=K) {
        ans1=c;
    }
    return max(ans,ans1);
}

Compilation message (stderr)

closing.cpp: In function 'void file()':
closing.cpp:17:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     freopen("input.txt","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
closing.cpp:18:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |     freopen("output.txt","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
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