Submission #714809

#	Time	Username	Problem	Language	Result	Execution time	Memory
714809		Nelt	Stranded Far From Home (BOI22_island)	C++17	10 / 100	1091 ms	108412 KiB

island

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,avx2,fma")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

/* DEFINES */
#define F first
#define S second
#define ll long long
#define ull unsigned long long
#define ld long double
#define npos ULLONG_MAX
#define INF LLONG_MAX
#define vv(a) vector<a>
#define pp(a, b) pair<a, b>
#define pq(a) priority_queue<a>
#define qq(a) queue<a>
#define ss(a) set<a>
#define mm(a, b) map<a, b>
#define ump(a, b) unordered_map<a, b>
#define sync                      \
    ios_base::sync_with_stdio(0); \
    cin.tie(0);                   \
    cout.tie(0);
#define elif else if
#define endl "\n"
#define allc(a) begin(a), end(a)
#define all(a) a, a + sizeof(a) / sizeof(a[0])
#define pb push_back
#define logi(a) __lg(a)
#define sqrt(a) sqrtl(a)
#define mpr make_pair
#define ins insert
using namespace std;
using namespace __gnu_pbds;
using namespace __cxx11;
typedef char chr;
typedef basic_string<chr> str;
template <typename T, typename key = less<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll N = 2e5 + 5;
vv(ll) g[N];
ll a[N], sub[N];
ll pref[N], ans[N];
multiset<ll> s;
void dfs(ll v, ll par = 0)
{
    sub[v] = a[v];
    pref[v] = pref[par] + a[v];
    ans[v] = (sub[v] >= a[par]) and ans[par];
    s.ins(a[v] + pref[v]);
    for (ll to : g[v])
        if (to != par)
            dfs(to, v), sub[v] += sub[to];
    s.erase(s.find(a[v] + pref[v]));
}
void solve()
{
    ans[0] = 1;
    ll n, m;
    cin >> n >> m;
    for (ll i = 1; i <= n; i++)
        cin >> a[i];
    while (m--)
    {
        ll x, y;
        cin >> x >> y;
        g[x].pb(y);
        g[y].pb(x);
    }
    if (n <= 2010)
    {
        ss(pp(ll, ll)) s;
        bool us[n + 1];
        for (ll i = 1; i <= n; i++)
        {
            memset(us, 0, sizeof(us));
            s.clear();
            for (ll j : g[i])
                s.ins(mpr(a[j], j));
            us[i] = 1;
            ll val = a[i];
            while (!s.empty() and s.begin()->F <= val)
            {
                auto tmp = *s.begin();
                us[tmp.S] = 1;
                val += tmp.F;
                for (ll to : g[tmp.S])
                    if (!us[to])
                        s.ins(mpr(a[to], to));
                s.erase(tmp);
            }
            if (count(us + 1, us + n + 1, 0))
                cout << "0";
            else
                cout << "1";
        }
        cout << endl;
        return;
    }
    dfs(1);
    for (ll i = 1; i <= n; i++)
        cout << ans[i];
    cout << endl;
}
/*

*/
int main()
{
    sync
        // precomp();
        ll t = 1;
    // cin >> t;
    for (ll i = 1; i <= t; i++)
        // cout << "Case " << i << ": ",
        solve();
    cerr << "\nTime elapsed : " << clock() * 1000.0 / CLOCKS_PER_SEC << " ms\n";
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 30
• Subtask 5: 0 / 35