oj.uz

Submission #77026

# Submission time Handle Problem Language Result Execution time Memory
77026 2018-09-20T06:52:45 Z samuelfgs96 Beads and wires (APIO14_beads) C++11
100 / 100
 489 ms 40088 KB 
#include<bits/stdc++.h>

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define eb emplace_back

using namespace std;

typedef pair<int, int> pii;
typedef long long ll;

const int N = 212345;
int dp[N][2], pai[N];
vector <pii> g[N];
void lul (int u, int pu) {
	for (auto v : g[u]) 
		if (v.fi != pu) {
			pai[v.fi] = u;
			lul(v.fi, u);
		}
	
}
int solve (int u, int cor, int pu) {
	int &ans = dp[u][cor];
	if (ans != -1) return ans;
	ans = -0x3f3f3f3f;
	if (cor == 0) { //os filhos podem ser qualquer coisa
		ans = 0;
		for (auto q : g[u]) {
			int v, w; tie(v, w) = q;
			if (v == pu) continue;
			ans += max(solve(v, 0, u), solve(v, 1, u) + w);
		}
	} else { //um filho tem que ser azul
		vector <int> st[3];
		vector <int> xd;
		for (auto q : g[u]) {
			int v, w; tie(v, w) = q;
			if (v == pu) continue;
			st[0].pb(solve(v, 0, u));
			st[1].pb(solve(v, 1, u) + w);
			st[2].pb(solve(v, 0, u) + w);
			xd.pb(v);
		}
		if (st[0].empty()) return ans;
		int best_id = 0, best = st[2][0] - max(st[0][0], st[1][0]);
		ans = 0;
		for (int i = 0; i < st[0].size(); i++) {
			int value = max(st[0][i], st[1][i]);
			int lucro = st[2][i] - value;
			if (lucro > best) {
				best = lucro;
				best_id = i;
			}
		}
		for (int i = 0; i < st[0].size(); i++)
			if (best_id == i) ans += st[2][i];
			else ans += max(st[0][i], st[1][i]);
	}
	return ans;
}
int ans;
void dfs (int u, int pu, int a, int b) {
	{
		int tmp = 0;
		for (auto q : g[u]) {
			int v, w; tie(v, w) = q;
			if (v == pu) tmp += max(a, b + w);
			else tmp += max(dp[v][0], dp[v][1] + w);
		}
		ans = max(ans, tmp);
	}
	int na = 0, nb = 0;
	for (auto q : g[u]) {
		int v, w; tie(v, w) = q;
		if (v == pu) na += max(a, b + w);
		else na += max(dp[v][0], dp[v][1] + w);
	}
	vector <pii> st[4];
	int ct = 0;
	vector <int> xd;
	for (auto q : g[u]) {
		int v, w; tie(v, w) = q;
		if (v == pu) {
			st[0].eb(a, -1);
			st[1].eb(b + w, -1);
			st[2].eb(a + w, -1);

			st[3].eb(a + w - max(a, b + w), ct++);
			xd.pb(-1);
		} else {
			st[0].eb(dp[v][0], v);
			st[1].eb(dp[v][1] + w, v);
			st[2].eb(dp[v][0] + w, v);

			st[3].eb(dp[v][0] + w - max(dp[v][0], dp[v][1] + w), ct++);
			xd.pb(v);
		}
	}
	sort(st[3].rbegin(), st[3].rend());
	for (int i = 0; i < st[3].size(); i++)
		nb += max(st[0][i].fi, st[1][i].fi);
	for (auto q : g[u]) {
		int v, w; tie(v, w) = q;
		if (v == pu) continue;
		if (st[3].size() == 1) {
			dfs(v, u, na - max(dp[v][0], dp[v][1] + w), -0x3f3f3f3f);
			continue;
		}

		int aqui = nb;
		aqui -= max(dp[v][0], dp[v][1] + w);
		int k = st[3][0].se;
		if (xd[st[3][0].se] == v) { //pegar o segundo
			k = st[3][1].se;
		}
		aqui -= max(st[0][k].fi, st[1][k].fi);
		aqui += st[2][k].fi;
		dfs(v, u, na - max(dp[v][0], dp[v][1] + w), aqui);
	}
}
int main (void) {
	int n; scanf("%d", &n);
	for (int i = 1; i < n; i++) {
		int u, v, w; scanf("%d %d %d", &u, &v, &w);
		g[u].eb(v, w);
		g[v].eb(u, w);
	}
	memset (dp, -1, sizeof dp);
	lul(1, 0);
	for (int i = 1; i <= n; i++) {
		solve(i, 0, pai[i]);
		solve(i, 1, pai[i]);
	}

	dfs(1, 0, 0, 0);
	cout << ans << endl;
	return 0;
}

Compilation message

beads.cpp: In function 'int solve(int, int, int)':
beads.cpp:50:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < st[0].size(); i++) {
                   ~~^~~~~~~~~~~~~~
beads.cpp:58:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < st[0].size(); i++)
                   ~~^~~~~~~~~~~~~~
beads.cpp: In function 'void dfs(int, int, int, int)':
beads.cpp:103:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < st[3].size(); i++)
                  ~~^~~~~~~~~~~~~~
beads.cpp: In function 'int main()':
beads.cpp:125:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  int n; scanf("%d", &n);
         ~~~~~^~~~~~~~~~
beads.cpp:127:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int u, v, w; scanf("%d %d %d", &u, &v, &w);
                ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 6912 KB Output is correct
2 Correct 7 ms 7040 KB Output is correct
3 Correct 8 ms 7040 KB Output is correct
4 Correct 7 ms 7040 KB Output is correct
5 Correct 8 ms 7040 KB Output is correct
6 Correct 7 ms 7040 KB Output is correct
7 Correct 7 ms 6912 KB Output is correct
8 Correct 7 ms 7040 KB Output is correct
9 Correct 7 ms 7040 KB Output is correct
10 Correct 7 ms 6912 KB Output is correct
11 Correct 7 ms 7040 KB Output is correct
12 Correct 7 ms 7040 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 6912 KB Output is correct
2 Correct 7 ms 7040 KB Output is correct
3 Correct 8 ms 7040 KB Output is correct
4 Correct 7 ms 7040 KB Output is correct
5 Correct 8 ms 7040 KB Output is correct
6 Correct 7 ms 7040 KB Output is correct
7 Correct 7 ms 6912 KB Output is correct
8 Correct 7 ms 7040 KB Output is correct
9 Correct 7 ms 7040 KB Output is correct
10 Correct 7 ms 6912 KB Output is correct
11 Correct 7 ms 7040 KB Output is correct
12 Correct 7 ms 7040 KB Output is correct
13 Correct 8 ms 7040 KB Output is correct
14 Correct 7 ms 6912 KB Output is correct
15 Correct 8 ms 7044 KB Output is correct
16 Correct 8 ms 6912 KB Output is correct
17 Correct 8 ms 6912 KB Output is correct
18 Correct 8 ms 7040 KB Output is correct
19 Correct 8 ms 7000 KB Output is correct
20 Correct 8 ms 6912 KB Output is correct
21 Correct 9 ms 7040 KB Output is correct
22 Correct 8 ms 7040 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 6912 KB Output is correct
2 Correct 7 ms 7040 KB Output is correct
3 Correct 8 ms 7040 KB Output is correct
4 Correct 7 ms 7040 KB Output is correct
5 Correct 8 ms 7040 KB Output is correct
6 Correct 7 ms 7040 KB Output is correct
7 Correct 7 ms 6912 KB Output is correct
8 Correct 7 ms 7040 KB Output is correct
9 Correct 7 ms 7040 KB Output is correct
10 Correct 7 ms 6912 KB Output is correct
11 Correct 7 ms 7040 KB Output is correct
12 Correct 7 ms 7040 KB Output is correct
13 Correct 8 ms 7040 KB Output is correct
14 Correct 7 ms 6912 KB Output is correct
15 Correct 8 ms 7044 KB Output is correct
16 Correct 8 ms 6912 KB Output is correct
17 Correct 8 ms 6912 KB Output is correct
18 Correct 8 ms 7040 KB Output is correct
19 Correct 8 ms 7000 KB Output is correct
20 Correct 8 ms 6912 KB Output is correct
21 Correct 9 ms 7040 KB Output is correct
22 Correct 8 ms 7040 KB Output is correct
23 Correct 14 ms 7296 KB Output is correct
24 Correct 13 ms 7168 KB Output is correct
25 Correct 13 ms 7168 KB Output is correct
26 Correct 19 ms 7424 KB Output is correct
27 Correct 19 ms 7424 KB Output is correct
28 Correct 16 ms 8072 KB Output is correct
29 Correct 16 ms 7768 KB Output is correct
30 Correct 17 ms 7768 KB Output is correct
31 Correct 21 ms 9472 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 6912 KB Output is correct
2 Correct 7 ms 7040 KB Output is correct
3 Correct 8 ms 7040 KB Output is correct
4 Correct 7 ms 7040 KB Output is correct
5 Correct 8 ms 7040 KB Output is correct
6 Correct 7 ms 7040 KB Output is correct
7 Correct 7 ms 6912 KB Output is correct
8 Correct 7 ms 7040 KB Output is correct
9 Correct 7 ms 7040 KB Output is correct
10 Correct 7 ms 6912 KB Output is correct
11 Correct 7 ms 7040 KB Output is correct
12 Correct 7 ms 7040 KB Output is correct
13 Correct 8 ms 7040 KB Output is correct
14 Correct 7 ms 6912 KB Output is correct
15 Correct 8 ms 7044 KB Output is correct
16 Correct 8 ms 6912 KB Output is correct
17 Correct 8 ms 6912 KB Output is correct
18 Correct 8 ms 7040 KB Output is correct
19 Correct 8 ms 7000 KB Output is correct
20 Correct 8 ms 6912 KB Output is correct
21 Correct 9 ms 7040 KB Output is correct
22 Correct 8 ms 7040 KB Output is correct
23 Correct 14 ms 7296 KB Output is correct
24 Correct 13 ms 7168 KB Output is correct
25 Correct 13 ms 7168 KB Output is correct
26 Correct 19 ms 7424 KB Output is correct
27 Correct 19 ms 7424 KB Output is correct
28 Correct 16 ms 8072 KB Output is correct
29 Correct 16 ms 7768 KB Output is correct
30 Correct 17 ms 7768 KB Output is correct
31 Correct 21 ms 9472 KB Output is correct
32 Correct 88 ms 9208 KB Output is correct
33 Correct 89 ms 9080 KB Output is correct
34 Correct 87 ms 9080 KB Output is correct
35 Correct 448 ms 15324 KB Output is correct
36 Correct 429 ms 15480 KB Output is correct
37 Correct 456 ms 15472 KB Output is correct
38 Correct 311 ms 24332 KB Output is correct
39 Correct 301 ms 25024 KB Output is correct
40 Correct 311 ms 22332 KB Output is correct
41 Correct 489 ms 40088 KB Output is correct