Submission #597935

#	Time	Username	Problem	Language	Result	Execution time	Memory
597935		maomao90	Stranded Far From Home (BOI22_island)	C++17	100 / 100	491 ms	79156 KiB

island

#include <bits/stdc++.h>
using namespace std;

#define REP(i, j, k) for (int i = j; i < k; i++)
#define RREP(i, j, k) for (int i = j; i >= k; i--)

template <class T>
inline bool mnto(T &a, const T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T &a, const T b) {return a < b ? a = b, 1 : 0;}

typedef long long ll;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define ALL(x) x.begin(), x.end()
#define SZ(x) (int) x.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef tuple<int, int, int> iii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

const int MAXN = 300005;
const int INF = 1000000005;
const ll LINF = 1000000000000000005;
const int MAXL = 20;

int n, m;
int s[MAXN];
set<ii> adj[MAXN];
bool vis[MAXN];
int ap[MAXN];
bool ans[MAXN];

ll sm[MAXN];
int p[MAXN], rnk[MAXN];
void init() {
    REP (i, 1, n + 1) {
	sm[i] = s[i];
	p[i] = i;
	rnk[i] = 1;
    }
}
int findp(int i) {
    if (p[i] == i) return i;
    return p[i] = findp(p[i]);
}
bool join(int a, int b) {
    int pa = findp(a), pb = findp(b);
    if (pa == pb) return 0;
    if (rnk[pa] < rnk[pb]) swap(pa, pb);
    if (rnk[pa] == rnk[pb]) rnk[pa]++;
    p[pb] = pa;
    sm[pa] += sm[pb];
    if (adj[pa].size() < adj[pb].size()) {
	swap(adj[pa], adj[pb]);
    }
    for (ii v : adj[pb]) {
	adj[pa].insert(v);
    }
    return 1;
}

int main() {
#ifndef DEBUG
    ios::sync_with_stdio(0), cin.tie(0);
#endif
    cin >> n >> m;
    REP (i, 1, n + 1) {
	cin >> s[i];
    }
    REP (i, 0, m) {
	int u, v; cin >> u >> v;
	adj[u].insert({s[v], v});
	adj[v].insert({s[u], u});
    }

    init();
    vi id(n, 0);
    iota(ALL(id), 1);
    sort(ALL(id), [&] (int l, int r) {
	    return s[l] < s[r];
	    });
    for (int u : id) {
	vis[u] = 1;
	vi toj;
	for (auto [w, v] : adj[u]) {
	    if (vis[v]) {
		toj.pb(v);
	    }
	}
	cerr << u << '\n';
	for (int v : toj) {
	    cerr << u << " <-> " << v << '\n';
	    join(u, v);
	}
	int fp = findp(u);
	while (!adj[fp].empty() && vis[findp(adj[fp].begin() -> SE)]) {
	    adj[fp].erase(adj[fp].begin());
	}
	ap[u] = -1;
	if (!adj[fp].empty() && sm[fp] >= adj[fp].begin() -> FI) {
	    ap[u] = adj[fp].begin() -> SE;
	}
    }
    reverse(ALL(id));
    ans[id[0]] = 1;
    for (int u : id) {
	cerr << u << ": " << ap[u] << '\n';
	if (ap[u] == -1) continue;
	ans[u] = ans[ap[u]];
    }

    REP (i, 1, n + 1) {
	cout << ans[i];
    }
    cout << '\n';
    return 0;
}

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