Submission #475782

# Submission time Handle Problem Language Result Execution time Memory
475782 2021-09-24T04:38:44 Z maomao90 Aesthetic (NOI20_aesthetic) C++17
35 / 100
2000 ms 56720 KB
#include <bits/stdc++.h> 
using namespace std;

template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
#define REP(i, s, e) for (int i = s; i < e; i++)
#define RREP(i, s, e) for (int i = s; i >= e; i--)
typedef long long ll;
typedef long double ld;
#define MP make_pair
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define MT make_tuple
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;

#ifdef DEBUG
#define debug(args...) printf(args)
#else
#define debug(args...)
#endif

#define INF 1000000005
#define LINF 1000000000000000005
#define MOD 1000000007
#define MAXN 300005

struct edge {
	int v, w, p;
};

int n, m;
vector<edge> adj[MAXN];
int a[MAXN], b[MAXN], w[MAXN], p[MAXN];
ll base;

priority_queue<pll, vector<pll>, greater<pll>> pq;
ll d1[MAXN], dn[MAXN];
void dij(int s, ll* d) {
	REP (i, 1, n + 1) {
		d[i] = LINF;
	}
	d[s] = 0;
	pq.push(MP(0, s));
	while (!pq.empty()) {
		auto [ud, u] = pq.top(); pq.pop();
		if (ud != d[u]) continue;
		for (edge e : adj[u]) {
			if (mnto(d[e.v], ud + e.w)) {
				pq.push(MP(d[e.v], e.v));
			}
		}
	}
}

ll x;
bool res;
int pre[MAXN], top[MAXN], ptr;
vector<edge> nadj[MAXN];
void dfs(int u, int p) {
	pre[u] = top[u] = ptr++;
	for (edge e : nadj[u]) {
		if (e.v == p) continue;
		if (pre[e.v] == -1) {
			dfs(e.v, u);
			mnto(top[u], top[e.v]);
			if (top[e.v] > pre[u]) {
				if ((min(d1[u] + dn[e.v], d1[e.v] + dn[u])
					   	+ e.w + e.p > x + base) && 
						pre[n] != -1 && 
						pre[n] >= pre[e.v])	{
					res = 1;
				}
			}
		} else {
			mnto(top[u], pre[e.v]);
		}
	}
}

bool isPos(ll x) {
	REP (i, 1, n + 1) {
		nadj[i].clear();
	}
	debug("%lld\n", x);
	REP (i, 0, m) {
		if (min(d1[a[i]] + dn[b[i]], d1[b[i]] + dn[a[i]]) + w[i] <= x + base) {
			debug(" %d %d %d\n", a[i], b[i], p[i]);
			debug("  %lld + %d + %d\n", min(d1[a[i]] + dn[b[i]], d1[b[i]] + dn[a[i]]), w[i], p[i]);
			nadj[a[i]].pb({b[i], w[i], p[i]});
			nadj[b[i]].pb({a[i], w[i], p[i]});
		}
	}
	ptr = 0;
	::x = x;
	res = 0;
	memset(pre, -1, sizeof pre);
	dfs(1, -1);
	return res;
}

int main() {
	scanf("%d%d", &n, &m);
	REP (i, 0, m) {
		scanf("%d%d%d", &a[i], &b[i], &w[i]);
	}
	int mx = 0;
	RREP (i, m - 1, 0) {
		p[i] = mx;
		mxto(mx, w[i]);
	}
	REP (i, 0, m) {
		adj[a[i]].pb({b[i], w[i], p[i]});
		adj[b[i]].pb({a[i], w[i], p[i]});
	}
	dij(1, d1);
	dij(n, dn);
	base = d1[n];
	ll lo = 0, hi = INF, mid;
	while (lo < hi) {
		mid = lo + hi + 1 >> 1;
		if (isPos(mid)) {
			lo = mid;
		} else {
			hi = mid - 1;
		}
	}
	printf("%lld\n", base + lo + 1);
	return 0;
}

Compilation message

Aesthetic.cpp: In function 'int main()':
Aesthetic.cpp:129:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  129 |   mid = lo + hi + 1 >> 1;
      |         ~~~~~~~~^~~
Aesthetic.cpp:111:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  111 |  scanf("%d%d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~
Aesthetic.cpp:113:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |   scanf("%d%d%d", &a[i], &b[i], &w[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 10 ms 15564 KB Output is correct
2 Correct 9 ms 15564 KB Output is correct
3 Correct 9 ms 15564 KB Output is correct
4 Correct 9 ms 15564 KB Output is correct
5 Correct 9 ms 15564 KB Output is correct
6 Correct 8 ms 15564 KB Output is correct
7 Correct 10 ms 15564 KB Output is correct
8 Correct 9 ms 15564 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 10 ms 15564 KB Output is correct
2 Correct 9 ms 15564 KB Output is correct
3 Correct 9 ms 15564 KB Output is correct
4 Correct 9 ms 15564 KB Output is correct
5 Correct 9 ms 15564 KB Output is correct
6 Correct 8 ms 15564 KB Output is correct
7 Correct 10 ms 15564 KB Output is correct
8 Correct 9 ms 15564 KB Output is correct
9 Correct 10 ms 15692 KB Output is correct
10 Correct 10 ms 15692 KB Output is correct
11 Correct 12 ms 15744 KB Output is correct
12 Correct 13 ms 15692 KB Output is correct
13 Correct 11 ms 15820 KB Output is correct
14 Correct 10 ms 15860 KB Output is correct
15 Correct 12 ms 15828 KB Output is correct
16 Correct 12 ms 15820 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 553 ms 38376 KB Output is correct
2 Correct 483 ms 38364 KB Output is correct
3 Correct 599 ms 38212 KB Output is correct
4 Correct 562 ms 38244 KB Output is correct
5 Correct 595 ms 38264 KB Output is correct
6 Correct 528 ms 39016 KB Output is correct
7 Correct 635 ms 38632 KB Output is correct
8 Correct 580 ms 38728 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 571 ms 39028 KB Output is correct
2 Correct 526 ms 38524 KB Output is correct
3 Correct 508 ms 37956 KB Output is correct
4 Correct 551 ms 38080 KB Output is correct
5 Correct 526 ms 38392 KB Output is correct
6 Correct 515 ms 38356 KB Output is correct
7 Correct 548 ms 38552 KB Output is correct
8 Correct 524 ms 38756 KB Output is correct
# Verdict Execution time Memory Grader output
1 Execution timed out 2082 ms 56720 KB Time limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Execution timed out 2082 ms 56720 KB Time limit exceeded
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 10 ms 15564 KB Output is correct
2 Correct 9 ms 15564 KB Output is correct
3 Correct 9 ms 15564 KB Output is correct
4 Correct 9 ms 15564 KB Output is correct
5 Correct 9 ms 15564 KB Output is correct
6 Correct 8 ms 15564 KB Output is correct
7 Correct 10 ms 15564 KB Output is correct
8 Correct 9 ms 15564 KB Output is correct
9 Correct 10 ms 15692 KB Output is correct
10 Correct 10 ms 15692 KB Output is correct
11 Correct 12 ms 15744 KB Output is correct
12 Correct 13 ms 15692 KB Output is correct
13 Correct 11 ms 15820 KB Output is correct
14 Correct 10 ms 15860 KB Output is correct
15 Correct 12 ms 15828 KB Output is correct
16 Correct 12 ms 15820 KB Output is correct
17 Correct 553 ms 38376 KB Output is correct
18 Correct 483 ms 38364 KB Output is correct
19 Correct 599 ms 38212 KB Output is correct
20 Correct 562 ms 38244 KB Output is correct
21 Correct 595 ms 38264 KB Output is correct
22 Correct 528 ms 39016 KB Output is correct
23 Correct 635 ms 38632 KB Output is correct
24 Correct 580 ms 38728 KB Output is correct
25 Correct 571 ms 39028 KB Output is correct
26 Correct 526 ms 38524 KB Output is correct
27 Correct 508 ms 37956 KB Output is correct
28 Correct 551 ms 38080 KB Output is correct
29 Correct 526 ms 38392 KB Output is correct
30 Correct 515 ms 38356 KB Output is correct
31 Correct 548 ms 38552 KB Output is correct
32 Correct 524 ms 38756 KB Output is correct
33 Execution timed out 2082 ms 56720 KB Time limit exceeded
34 Halted 0 ms 0 KB -