Submission #1066761

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066761		mispertion	Stranded Far From Home (BOI22_island)	C++17	100 / 100	345 ms	85240 KiB

island

#include <bits/stdc++.h>

using namespace std;
#pragma GCC optimize("Ofast")

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef long long ll;
#define int ll
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define pb push_back
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define mispertion ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define F first
#define S second
#define getlast(s) (*s.rbegin())
#define debg cout << "OK\n"

const ld PI = 3.1415926535;
const int N = 3e5 + 10;
const int M = 1e5 + 10;
int mod = 998244353;
const int infi = INT_MAX;
const ll infl = 1e16;
const int P = 2;

int mult(int a, int b){
    return a * 1LL * b % mod;
}

int sum(int a, int b){
    if(a + b >= mod)
        return a + b - mod;
    if(a + b < 0)
        return a + b + mod;
    return a + b;
}

int binpow(int a, int n){
    if (n == 0)
        return 1;
    if (n % 2 == 1){
        return mult(binpow(a, n - 1), a);
    }
    else{
        auto b = binpow(a, n / 2);
        return mult(b, b);
    }
}

int n, m, s[N], zav[N], ans[N];
map<int, vector<int>> mp;
vector<int> g[N];

struct dsu{
    set<pii> nbr[N];
    int p[N], sz[N], sm[N];

    dsu(int n){
        for(int i = 1; i <= n; i++){
            p[i] = i;
            sz[i] = 1;
            sm[i] = s[i];
            for(auto u : g[i])
                if(s[u] > s[i])
                    nbr[i].insert({s[u], u});
        }
    }

    int getp(int v){
        if(p[v] == v)
            return v;
        return p[v] = getp(p[v]);
    }

    void uni(int a, int b){
        a = getp(a);
        b = getp(b);
        if(a == b)
            return;
        if(sz[a] > sz[b])   
            swap(a, b);
        p[a] = b;
        sz[b] += sz[a];
        sm[b] += sm[a];
        if(sz(nbr[b]) > sz(nbr[a])){
            while(sz(nbr[a]) > 0){
                nbr[b].insert(*nbr[a].begin());
                nbr[a].erase(nbr[a].begin());
            }
        }else{
            set<pii> tmp = nbr[b];
            nbr[b].swap(nbr[a]);
            for(auto e : tmp)
                nbr[b].insert(e);
        }
    }
};

void solve(){
    cin >> n >> m;
    vector<pii> por = {};
    for(int i = 1; i <= n; i++){
        ans[i] = -1;
        cin >> s[i];
        por.pb({s[i], i});
        mp[s[i]].pb(i);
    }
    sort(all(por));
    reverse(all(por));
    for(int i = 1; i <= m; i++){
        int u, v;
        cin >> u >> v;
        g[v].pb(u);
        g[u].pb(v);
    }
    dsu ds = dsu(n);
    for(auto e : mp){
        int w = e.F;
        for(auto v : e.S){
            for(auto u : g[v]){
                if(s[u] <= s[v])
                    ds.uni(u, v);
            }
        }
        for(auto v : e.S){
            int nv = ds.getp(v);
            while(sz(ds.nbr[nv]) > 0 && ds.nbr[nv].begin()->F <= w)
                ds.nbr[nv].erase(ds.nbr[nv].begin());
            if(sz(ds.nbr[nv]) == 0){
                ans[v] = 1;
            }else{
                if(ds.nbr[nv].begin()->F <= ds.sm[nv]){
                    zav[v] = ds.nbr[nv].begin()->S;
                }else{
                    ans[v] = 0;
                }
            }
        }
    }
    for(auto e : por){
        if(ans[e.S] == -1){
            ans[e.S] = ans[zav[e.S]];
        }
    }
    for(int i = 1; i <= n; i++)
        cout << ans[i];
    cout << '\n';
}

signed main(){
    mispertion;
    int t = 1;
    //cin >> t;
    while (t--){
        solve();
    }
    return 0;
}

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