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Submission #30646

# Submission time Handle Problem Language Result Execution time Memory
30646 2017-07-25T20:03:11 Z ulna Beads and wires (APIO14_beads) C++11
100 / 100
 429 ms 32664 KB 
#include <bits/stdc++.h>
using namespace std;

// why am I so weak

int n;

struct edge {int to; long long cost;};

vector<edge> g[200055];

inline void add_edge(int from, int to, int cost) {
	g[from].push_back((edge){to, cost});
}

long long dp[200055][2];

void dfs(int v, int par = -1) {
	dp[v][0] = 0;
	dp[v][1] = -(long long)1e13;
	
	// one dp[e.to][0] + e.cost
	
	long long sum = 0ll;

	for (auto e : g[v]) if (e.to != par) {
		dfs(e.to, v);

		dp[v][0] += max(dp[e.to][0], dp[e.to][1] + e.cost);
		sum += max(dp[e.to][0], dp[e.to][1] + e.cost);
	}

	for (auto e : g[v]) if (e.to != par) {
		dp[v][1] = max(dp[v][1], sum - max(dp[e.to][0], dp[e.to][1] + e.cost) + dp[e.to][0] + e.cost);
	}
}

struct dat {long long dat[2];};

long long rdfs(int v, int par, dat ac, long long cost) {
	long long res = dp[v][0] + max(ac.dat[0], ac.dat[1] + cost);

	dat cool;
	cool.dat[0] = 0;
	cool.dat[1] = -(long long)1e13;

	multiset<long long> s;
	long long sum = 0;

	for (auto e : g[v]) if (e.to != par) {
		cool.dat[0] += max(dp[e.to][0], dp[e.to][1] + e.cost);
		sum += max(dp[e.to][0], dp[e.to][1] + e.cost);
		
		s.insert(-max(dp[e.to][0], dp[e.to][1] + e.cost) + dp[e.to][0] + e.cost);
	}

	cool.dat[0] += max(ac.dat[0], ac.dat[1] + cost);
	sum += max(ac.dat[0], ac.dat[1] + cost);

	s.insert(-max(ac.dat[0], ac.dat[1] + cost) + ac.dat[0] + cost);

	for (auto e : g[v]) if (e.to != par) {
		s.erase(s.find(-max(dp[e.to][0], dp[e.to][1] + e.cost) + dp[e.to][0] + e.cost));

		cool.dat[0] -= max(dp[e.to][0], dp[e.to][1] + e.cost);
		cool.dat[1] = sum + *s.rbegin() - max(dp[e.to][0], dp[e.to][1] + e.cost);

		res = max(res, rdfs(e.to, v, cool, e.cost));
		
		cool.dat[0] += max(dp[e.to][0], dp[e.to][1] + e.cost);

		s.insert(-max(dp[e.to][0], dp[e.to][1] + e.cost) + dp[e.to][0] + e.cost);
	}

	return res;
}
int main() {
	scanf("%d", &n);

	for (int i = 1; i < n; i++) {
		int x, y, z;
		scanf("%d %d %d", &x, &y, &z);
		x--, y--;

		add_edge(x, y, z);
		add_edge(y, x, z);
	}

	dfs(0);

	dat a;
	a.dat[0] = 0;
	a.dat[1] = -(long long)1e13;
	
	printf("%lld\n", rdfs(0, -1, a, -(long long)1e13));

	return 0;
}

Compilation message

beads.cpp: In function 'int main()':
beads.cpp:78:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
beads.cpp:82:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d", &x, &y, &z);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 6 ms 4992 KB Output is correct
7 Correct 6 ms 4992 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 7 ms 4992 KB Output is correct
11 Correct 6 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 6 ms 4992 KB Output is correct
7 Correct 6 ms 4992 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 7 ms 4992 KB Output is correct
11 Correct 6 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 5 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 6 ms 5120 KB Output is correct
18 Correct 6 ms 5120 KB Output is correct
19 Correct 6 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 6 ms 4992 KB Output is correct
22 Correct 6 ms 5120 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 6 ms 4992 KB Output is correct
7 Correct 6 ms 4992 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 7 ms 4992 KB Output is correct
11 Correct 6 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 5 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 6 ms 5120 KB Output is correct
18 Correct 6 ms 5120 KB Output is correct
19 Correct 6 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 6 ms 4992 KB Output is correct
22 Correct 6 ms 5120 KB Output is correct
23 Correct 10 ms 5504 KB Output is correct
24 Correct 10 ms 5376 KB Output is correct
25 Correct 9 ms 5376 KB Output is correct
26 Correct 15 ms 5732 KB Output is correct
27 Correct 13 ms 5632 KB Output is correct
28 Correct 16 ms 6140 KB Output is correct
29 Correct 17 ms 6016 KB Output is correct
30 Correct 16 ms 5988 KB Output is correct
31 Correct 15 ms 6784 KB Output is correct

Subtask #4
43.0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 4992 KB Output is correct
2 Correct 6 ms 4992 KB Output is correct
3 Correct 6 ms 4992 KB Output is correct
4 Correct 6 ms 4992 KB Output is correct
5 Correct 6 ms 4992 KB Output is correct
6 Correct 6 ms 4992 KB Output is correct
7 Correct 6 ms 4992 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 6 ms 4992 KB Output is correct
10 Correct 7 ms 4992 KB Output is correct
11 Correct 6 ms 4992 KB Output is correct
12 Correct 6 ms 4992 KB Output is correct
13 Correct 6 ms 4992 KB Output is correct
14 Correct 5 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 5120 KB Output is correct
17 Correct 6 ms 5120 KB Output is correct
18 Correct 6 ms 5120 KB Output is correct
19 Correct 6 ms 5120 KB Output is correct
20 Correct 6 ms 5120 KB Output is correct
21 Correct 6 ms 4992 KB Output is correct
22 Correct 6 ms 5120 KB Output is correct
23 Correct 10 ms 5504 KB Output is correct
24 Correct 10 ms 5376 KB Output is correct
25 Correct 9 ms 5376 KB Output is correct
26 Correct 15 ms 5732 KB Output is correct
27 Correct 13 ms 5632 KB Output is correct
28 Correct 16 ms 6140 KB Output is correct
29 Correct 17 ms 6016 KB Output is correct
30 Correct 16 ms 5988 KB Output is correct
31 Correct 15 ms 6784 KB Output is correct
32 Correct 52 ms 8312 KB Output is correct
33 Correct 54 ms 8320 KB Output is correct
34 Correct 55 ms 8440 KB Output is correct
35 Correct 334 ms 18464 KB Output is correct
36 Correct 340 ms 18424 KB Output is correct
37 Correct 332 ms 18552 KB Output is correct
38 Correct 429 ms 26208 KB Output is correct
39 Correct 406 ms 27204 KB Output is correct
40 Correct 420 ms 26068 KB Output is correct
41 Correct 420 ms 32664 KB Output is correct