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Submission #26598

# Submission time Handle Problem Language Result Execution time Memory
26598 2017-07-03T12:27:15 Z Bruteforceman Beads and wires (APIO14_beads) C++11
57 / 100
 601 ms 9948 KB 
#include <bits/stdc++.h>
using namespace std;
int n;
vector <int> g[100010];
vector <int> c[100010];
long long dp[100010][2][2];
const long long inf = 1e16;

void dfs(int x, int par, int parCost) {
	for(size_t i = 0; i < g[x].size(); i++) {
		int y = g[x][i];
		int w = c[x][i];
		if(y == par) continue;
		dfs(y, x, w);
	}
	long long sum;
	vector <long long> best;
	
	// solves 10 case when node x is a middle node
	sum = 0;
	for(size_t i = 0; i < g[x].size(); i++) {
		int y = g[x][i];
		int cost = c[x][i];
		if(y == par) continue;
		long long add = max(dp[y][0][1], dp[y][0][0]);
		sum += add; 
	}
	for(size_t i = 0; i < g[x].size(); i++) {
		for(size_t j = 0; j < g[x].size(); j++) {
			if(i == j) continue;
			int p = g[x][i];
			int q = g[x][j];
			int pcost = c[x][i];
			int qcost = c[x][j];
			if(p == par || q == par) continue;
			
			long long opt = pcost + qcost + max(dp[p][1][0] + dp[q][0][0], dp[p][0][0] + dp[q][1][0]);
			long long del = max(dp[p][0][1], dp[p][0][0]) + max(dp[q][0][1], dp[q][0][0]);
			dp[x][1][0] = max(dp[x][1][0], opt + sum - del);
		}
	}
	// end case
	
	
	// solves 10 case when node x is not a middle node
	sum = 0;
	for(size_t i = 0; i < g[x].size(); i++) {
		int y = g[x][i];
		int cost = c[x][i];
		if(y == par) continue;
		long long add = max(dp[y][0][1], dp[y][0][0]);
		sum += add;
		best.push_back(max(dp[y][1][0], dp[y][1][1]) - add);
	}
	sort(best.begin(), best.end());
	reverse(best.begin(), best.end());
	if(best.size() > 0) dp[x][1][0] = max(dp[x][1][0], sum + best[0]);
	best.clear();
	// end case
	
	
	// solves 11 case
	sum = 0;
	for(size_t i = 0; i < g[x].size(); i++) {
		int y = g[x][i];
		int cost = c[x][i];
		if(y == par) continue;
		long long add = max(dp[y][0][1], dp[y][0][0]);
		sum += add;
		best.push_back(dp[y][1][0] - add + cost);
	}	
	sort(best.begin(), best.end());
	reverse(best.begin(), best.end());
	if(best.size() > 0) {
		dp[x][1][1] = sum + best[0] + parCost;
	} else {
		dp[x][1][1] = -inf;
	}
	best.clear();
	// end case
	
	
	// solves 01 case
	sum = 0;
	for(size_t i = 0; i < g[x].size(); i++) {
		int y = g[x][i];
		int cost = c[x][i];
		if(y == par) continue;
		long long add = max(dp[y][0][0], dp[y][0][1]);
		sum += add;
		best.push_back(dp[y][0][0] - add + cost);
	}
	sort(best.begin(), best.end());
	reverse(best.begin(), best.end());
	if(best.size() > 0) {
		dp[x][0][1] = sum + best[0] + parCost;
	} else {
		dp[x][0][1] = -inf;
	}
	best.clear();
	// end case
	
	// solves 00 case
	sum = 0;
	for(size_t i = 0; i < g[x].size(); i++) {
		int y = g[x][i];
		int cost = c[x][i];
		if(y == par) continue;
		long long add = max(dp[y][0][0], dp[y][0][1]);
		sum += add;
	}
	dp[x][0][0] = sum;
	// end case
}


int main() {
	scanf("%d", &n);
	for(int i = 1; i < n; i++) {
		int p, q, r;
		scanf("%d %d %d", &p, &q, &r);
		g[p].push_back(q);
		g[q].push_back(p);
		c[p].push_back(r);
		c[q].push_back(r);
	}
	dfs(1, 0, 0);
	long long ans = dp[1][1][0];
	printf("%lld\n", ans);	
	// cout << dp[6][1][0] << endl;
	// cout << dp[3][1][0] << endl;
	// cout << dp[2][0][1] << endl;
	// cout << dp[8][1][0] << endl;
	return 0;
}

Compilation message

beads.cpp: In function 'void dfs(int, int, int)':
beads.cpp:23:7: warning: unused variable 'cost' [-Wunused-variable]
   int cost = c[x][i];
       ^~~~
beads.cpp:49:7: warning: unused variable 'cost' [-Wunused-variable]
   int cost = c[x][i];
       ^~~~
beads.cpp:107:7: warning: unused variable 'cost' [-Wunused-variable]
   int cost = c[x][i];
       ^~~~
beads.cpp: In function 'int main()':
beads.cpp:118:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
beads.cpp:121:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d", &p, &q, &r);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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 5 ms 4992 KB Output is correct
6 Correct 5 ms 4992 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 6 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 5 ms 4992 KB Output is correct
6 Correct 5 ms 4992 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 6 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 5 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 4992 KB Output is correct
17 Correct 6 ms 4992 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 5120 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 5 ms 4992 KB Output is correct
6 Correct 5 ms 4992 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 6 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 5 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 4992 KB Output is correct
17 Correct 6 ms 4992 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 5120 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 5504 KB Output is correct
25 Correct 10 ms 5504 KB Output is correct
26 Correct 14 ms 6016 KB Output is correct
27 Correct 14 ms 6016 KB Output is correct
28 Correct 601 ms 6264 KB Output is correct
29 Correct 248 ms 6268 KB Output is correct
30 Correct 190 ms 6136 KB Output is correct
31 Correct 121 ms 6784 KB Output is correct

Subtask #4
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 5 ms 4992 KB Output is correct
6 Correct 5 ms 4992 KB Output is correct
7 Correct 5 ms 4992 KB Output is correct
8 Correct 6 ms 4992 KB Output is correct
9 Correct 5 ms 4992 KB Output is correct
10 Correct 6 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 5 ms 4992 KB Output is correct
14 Correct 6 ms 4992 KB Output is correct
15 Correct 6 ms 4992 KB Output is correct
16 Correct 6 ms 4992 KB Output is correct
17 Correct 6 ms 4992 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 5120 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 5504 KB Output is correct
25 Correct 10 ms 5504 KB Output is correct
26 Correct 14 ms 6016 KB Output is correct
27 Correct 14 ms 6016 KB Output is correct
28 Correct 601 ms 6264 KB Output is correct
29 Correct 248 ms 6268 KB Output is correct
30 Correct 190 ms 6136 KB Output is correct
31 Correct 121 ms 6784 KB Output is correct
32 Correct 62 ms 9908 KB Output is correct
33 Correct 58 ms 9848 KB Output is correct
34 Correct 66 ms 9948 KB Output is correct
35 Runtime error 11 ms 9856 KB Execution killed with signal 11 (could be triggered by violating memory limits)
36 Halted 0 ms 0 KB -