Submission #1145368

#	Time	Username	Problem	Language	Result	Execution time	Memory
1145368		Zbyszek99	Stranded Far From Home (BOI22_island)	C++20	100 / 100	530 ms	105656 KiB

island

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

vi graph[200'001];
set<pii> comp[200'001];
int comp_num[200'001];
vi comp_list[200'001];
ll comp_sum[200'001];
ll S[200'001];
int next_vert[200'001];
bool ans[200'001];

void union_(int a, int b)
{
    if(comp_num[a] == comp_num[b]) return;
    a = comp_num[a];
    b = comp_num[b];
    if(siz(comp_list[a]) > siz(comp_list[b]))
    {
        swap(a,b);
    }
    forall(it,comp[a])
    {
        comp[b].insert(it);
    }
    forall(it,comp_list[a])
    {
        comp_list[b].pb(it);
        comp_num[it] = b;
    }
    comp_sum[b] += comp_sum[a];
}

pii find_next(int v, int s)
{
    v = comp_num[v];
    while(!comp[v].empty())
    {
        auto it = comp[v].begin();
        if((*it).ff <= s) comp[v].erase(it);
        else break;
    }
    if(siz(comp[v]) != 0) return *comp[v].begin();
    return {-1,-1};
}


int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //random_start();
    int n,m;
    cin >> n >> m;
    rep2(i,1,n) cin >> S[i];
    rep2(i,1,n)
    {
        comp_num[i] = i;
        comp_list[i] = {i};
        comp_sum[i] = S[i];
    }
    rep(i,m)
    {
        int a,b;
        cin >> a >> b;
        comp[a].insert({S[b],b});
        comp[b].insert({S[a],a});
        if(S[a] >= S[b]) graph[a].pb(b);
        if(S[b] >= S[a]) graph[b].pb(a);
    }
    vector<pii> sort_v;
    rep2(i,1,n) sort_v.pb({S[i],i});
    sort(all(sort_v));
    int pop_val = -1;
    vi pop_vert;
    forall(it,sort_v)
    {
        if(it.ff != pop_val)
        {
            forall(it2,pop_vert)
            {
                pii nxt = find_next(it2,S[it2]);
        //        cout << it2 << " " << nxt.ss << " " << comp_num[it2] << " " <<  << " comp\n";
                if(nxt.ff == -1)
                {
                    next_vert[it2] = 0;
                    if(siz(comp_list[comp_num[it2]]) == n) ans[it2] = 1;
                }
                else if(nxt.ff <= comp_sum[comp_num[it2]])
                {
                    next_vert[it2] = nxt.ss;
                }
            }
            pop_vert = {};
        }
        pop_val = it.ff;
        pop_vert.pb(it.ss);
        forall(it2,graph[it.ss]) union_(it.ss,it2);
      //  cout << it.ss << " sort_v\n";
    }
    forall(it2,pop_vert)
    {
        pii nxt = find_next(it2,S[it2]);
        if(nxt.ff == -1)
        {
            next_vert[it2] = 0;
            if(siz(comp_list[comp_num[it2]]) == n) ans[it2] = 1;
        }
        else if(nxt.ff <= comp_sum[comp_num[it2]])
        {
            next_vert[it2] = nxt.ss;
        }
    }
    reverse(all(sort_v));
    forall(it,sort_v)
    {
        ans[it.ss] = ans[it.ss] || ans[next_vert[it.ss]];
    }
    rep2(i,1,n)
    {
        if(ans[i]) cout << 1;
        else cout << 0;
    }
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 30 / 30
• Subtask 5: 35 / 35