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Submission #677250

# Submission time Handle Problem Language Result Execution time Memory
677250 2023-01-02T16:18:06 Z vovamr Aesthetic (NOI20_aesthetic) C++17
35 / 100
 500 ms 29936 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define fi first
#define se second
#define ll long long
#define ld long double
#define sz(x) ((int)(x).size())
#define all(x) 	(x).begin(), (x).end()
#define pb push_back
#define mpp make_pair
#define ve vector
using namespace std;
using namespace __gnu_pbds;
template<class T> using oset = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
const ll inf = 1e18; const int iinf = 1e9;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T> inline bool chmin(T& a, T b) { return (a > b ? a = b, 1 : 0); }
template <typename T> inline bool chmax(T& a, T b) { return (a < b ? a = b, 1 : 0); }

const int N = 3e5 + 10;
const int M = 3e5 + 10;

ve<int> gr[N];

int n;

array<int,3> edges[M];
inline int go(const int &ID, const int &v) { return v ^ edges[ID][0] ^ edges[ID][1]; }

inline ve<ll> dij(const int &s) {
	ve<ll> d(n, inf); d[s] = 0;
	set<pll> st; st.insert({d[s], s});

	while (sz(st)) {
		int v = st.begin()->se;
		st.erase(st.begin());

		for (auto &id : gr[v]) {
			int to = go(id, v);
			int w = edges[id][2];

			if (d[to] > d[v] + w) {
				st.erase({d[to], to});
				d[to] = d[v] + w;
				st.insert({d[to], to});
			}
		}
	}
	return d;
}

inline void solve() {
	int m;
	cin >> n >> m;

	for (int i = 0; i < m; ++i) {
		int v, u, w;
		cin >> v >> u >> w;

		edges[i] = {--v, --u, w};

		gr[v].pb(i);
		gr[u].pb(i);
	}

	ve<int> sf(m);
	for (int i = m - 2; ~i; --i) {
		sf[i] = max(sf[i + 1], edges[i + 1][2]);
	}

	auto d0 = dij(0);
	auto d1 = dij(n - 1);

	auto can = [&](const ll &x) -> bool {

		int timer = 0;
		ve<int> in(n), up(n), used(n);

		bool ok = 0;

		function<void(int,int)> dfs = [&](int v, int pid) {
			used[v] = 1;
			in[v] = up[v] = timer++;

			for (auto &id : gr[v]) {
				int to = go(id, v);

				auto &[A, B, w] = edges[id];
				ll cs = min(d0[A] + d1[B], d1[A] + d0[B]) + w;

				if (cs >= x || id == pid) continue;

				if (used[to] == 1) {
					chmin(up[v], in[to]);
				}
				else if (!used[to]) {
					dfs(to, id);
					chmin(up[v], up[to]);

					if (up[to] > in[v] && in[n - 1] >= in[to] && cs + sf[id] >= x) {
						ok = 1;
					}
				}
			}
			used[v] = 2;
		};
		dfs(0, -1);

		return ok;
	};

	ll l = d0[n - 1], r = d0[n - 1] + sf[0], mid, ans;
	while (l <= r) {
		mid = l + r >> 1;
		if (can(mid)) ans = mid, l = mid + 1;
		else r = mid - 1;
	}
	cout << ans;
}

signed main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	int q = 1; // cin >> q;
	while (q--) solve();
	cerr << fixed << setprecision(3) << "Time execution: " << (double)clock() / CLOCKS_PER_SEC << endl;
}

Compilation message

Aesthetic.cpp: In function 'void solve()':
Aesthetic.cpp:117:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  117 |   mid = l + r >> 1;
      |         ~~^~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 4 ms 7380 KB Output is correct
3 Correct 5 ms 7380 KB Output is correct
4 Correct 4 ms 7380 KB Output is correct
5 Correct 4 ms 7328 KB Output is correct
6 Correct 4 ms 7380 KB Output is correct
7 Correct 4 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct

Subtask #2
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 4 ms 7380 KB Output is correct
3 Correct 5 ms 7380 KB Output is correct
4 Correct 4 ms 7380 KB Output is correct
5 Correct 4 ms 7328 KB Output is correct
6 Correct 4 ms 7380 KB Output is correct
7 Correct 4 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct
9 Correct 5 ms 7508 KB Output is correct
10 Correct 5 ms 7508 KB Output is correct
11 Correct 8 ms 7652 KB Output is correct
12 Correct 6 ms 7508 KB Output is correct
13 Correct 5 ms 7524 KB Output is correct
14 Correct 5 ms 7508 KB Output is correct
15 Correct 5 ms 7508 KB Output is correct
16 Correct 5 ms 7508 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 449 ms 29512 KB Output is correct
2 Correct 460 ms 29468 KB Output is correct
3 Correct 465 ms 29244 KB Output is correct
4 Correct 441 ms 29288 KB Output is correct
5 Correct 472 ms 29432 KB Output is correct
6 Correct 459 ms 29876 KB Output is correct
7 Correct 454 ms 29700 KB Output is correct
8 Correct 500 ms 29912 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 468 ms 29936 KB Output is correct
2 Correct 458 ms 29548 KB Output is correct
3 Correct 499 ms 29400 KB Output is correct
4 Correct 447 ms 29896 KB Output is correct
5 Correct 450 ms 29464 KB Output is correct
6 Correct 456 ms 29424 KB Output is correct
7 Correct 454 ms 29452 KB Output is correct
8 Correct 446 ms 29656 KB Output is correct

Subtask #5
0 / 16.0

# Verdict Execution time Memory Grader output
1 Incorrect 406 ms 27496 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 406 ms 27496 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #7
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 7380 KB Output is correct
2 Correct 4 ms 7380 KB Output is correct
3 Correct 5 ms 7380 KB Output is correct
4 Correct 4 ms 7380 KB Output is correct
5 Correct 4 ms 7328 KB Output is correct
6 Correct 4 ms 7380 KB Output is correct
7 Correct 4 ms 7380 KB Output is correct
8 Correct 4 ms 7380 KB Output is correct
9 Correct 5 ms 7508 KB Output is correct
10 Correct 5 ms 7508 KB Output is correct
11 Correct 8 ms 7652 KB Output is correct
12 Correct 6 ms 7508 KB Output is correct
13 Correct 5 ms 7524 KB Output is correct
14 Correct 5 ms 7508 KB Output is correct
15 Correct 5 ms 7508 KB Output is correct
16 Correct 5 ms 7508 KB Output is correct
17 Correct 449 ms 29512 KB Output is correct
18 Correct 460 ms 29468 KB Output is correct
19 Correct 465 ms 29244 KB Output is correct
20 Correct 441 ms 29288 KB Output is correct
21 Correct 472 ms 29432 KB Output is correct
22 Correct 459 ms 29876 KB Output is correct
23 Correct 454 ms 29700 KB Output is correct
24 Correct 500 ms 29912 KB Output is correct
25 Correct 468 ms 29936 KB Output is correct
26 Correct 458 ms 29548 KB Output is correct
27 Correct 499 ms 29400 KB Output is correct
28 Correct 447 ms 29896 KB Output is correct
29 Correct 450 ms 29464 KB Output is correct
30 Correct 456 ms 29424 KB Output is correct
31 Correct 454 ms 29452 KB Output is correct
32 Correct 446 ms 29656 KB Output is correct
33 Incorrect 406 ms 27496 KB Output isn't correct
34 Halted 0 ms 0 KB -