Submission #973964

#	Time	Username	Problem	Language	Result	Execution time	Memory
973964		c2zi6	Stranded Far From Home (BOI22_island)	C++14	20 / 100	1112 ms	397124 KiB

island

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<class T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

int n, m;
VI s;
VVI gp;
VI ans;

// n, m <= 2000
namespace TEST1 {
	void main() {
		rep(r, n) {
			VI vis(n);
			ll sum = s[r];
			vis[r] = true;
			priority_queue<PII> pq;
			for (int v : gp[r]) pq.push({-s[v], v});
			while (pq.size()) {
				int u = pq.top().ss;
				pq.pop();
				if (vis[u]) continue;
				if (sum >= s[u]) {
					sum += s[u];
					vis[u] = true;
					for (int v : gp[u]) if (!vis[v]) pq.push({-s[v], v});
				} else {
					break;
				}
			}
			bool kexni = true;
			rep(u, n) if (!vis[u]) kexni = false;
			ans[r] = kexni;
		}
	}
}

// tree 
namespace TEST2 {
	VL subsum;
	VI par;
	VI vat;
	void dfs1(int u = 0, int p = -1) {
		par[u] = p;
		subsum[u] = s[u];
		for (int v : gp[u]) if (v != p) {
			dfs1(v, u);
			subsum[u] += subsum[v];
		}
	}
	void dfs2(int u = 0, int p = -1) {
		if (u && vat[p]) vat[u] = true;
		for (int v : gp[u]) if (v != p) dfs2(v, u);
	}
	void main() {
		subsum = VL(n);
		par = VI(n);
		vat = VI(n);
		dfs1();
		replr(u, 1, n-1) {
			if (s[par[u]] > subsum[u]) vat[u] = true;
		}
		dfs2();
		rep(i, n) ans[i] = !vat[i];
	}
}

void solve() {
	cin >> n >> m;
	s = VI(n);
	for (int& x : s) cin >> x;
	gp = VVI(n);
	rep(i, m) {
		int u, v;
		cin >> u >> v;
		u--, v--;
		gp[u].pb(v);
		gp[v].pb(u);
	}
	ans = VI(n);
	if (n <= 2000 && m <= 2000) TEST1::main();
	else {
		TEST2::main();
	}
	for (int x : ans) cout << x; cout << endl;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    int t = 1;
    /* cin >> t; */
    while (t--) solve();
}

Compilation message (stderr)

island.cpp: In function 'void solve()':
island.cpp:113:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  113 |  for (int x : ans) cout << x; cout << endl;
      |  ^~~
island.cpp:113:31: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  113 |  for (int x : ans) cout << x; cout << endl;
      |                               ^~~~

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