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Submission #399267

# Submission time Handle Problem Language Result Execution time Memory
399267 2021-05-05T13:44:22 Z LucaDantas The Xana coup (BOI21_xanadu) C++17
100 / 100
 100 ms 23348 KB 
#include <bits/stdc++.h>
using namespace std;

constexpr int maxn = 1e5+10, inf = 0x3f3f3f3f;

vector<int> g[maxn];

int dp[maxn][2][2], new_dp[maxn][2][2], state[maxn];

void min_self(int& a, int b) { a = min(a, b); }

void dfs(int u, int p = 0) {
	dp[u][0][state[u]] = 0;
	dp[u][0][!state[u]] = inf;

	dp[u][1][state[u]] = inf;
	dp[u][1][!state[u]] = 1;

	for(int v : g[u]) {
		if(v == p) continue;
		dfs(v, u);

		for(int i : {0, 1}) { // vou me ativar ou n
			for(int j : {0, 1}) { // estou ligado ou desligado - ja contando a minha ativação
				for(int k : {0, 1}) { // ativo-inativo de v
					for(int l : {0, 1}) { // ligado-desligado de u
						if(i ^ l) continue; // n posso juntar pq eu preciso garantir q tá todo mundo desligado
						min_self(new_dp[u][i][j^k], dp[u][i][j] + dp[v][k][l]);
					}
				}
			}
		}

		for(int i : {0, 1}) for(int j : {0, 1})
			dp[u][i][j] = new_dp[u][i][j], new_dp[u][i][j] = inf;
	}
}

int main() {
	int n; scanf("%d", &n);
	for(int i = 1, a, b; i < n; i++)
		scanf("%d %d", &a, &b), g[a].push_back(b), g[b].push_back(a);
	for(int i = 1; i <= n; i++)
		scanf("%d", state + i);
	for(int u = 0; u < maxn; u++)
		for(int i : {0, 1}) for(int j : {0, 1})
			new_dp[u][i][j] = inf;
	dfs(1);
	int ans = min(dp[1][0][0], dp[1][1][0]);
	if(ans == inf) puts("impossible");
	else printf("%d\n", ans);
}

Compilation message

xanadu.cpp: In function 'int main()':
xanadu.cpp:40:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   40 |  int n; scanf("%d", &n);
      |         ~~~~~^~~~~~~~~~
xanadu.cpp:42:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   42 |   scanf("%d %d", &a, &b), g[a].push_back(b), g[b].push_back(a);
      |   ~~~~~^~~~~~~~~~~~~~~~~
xanadu.cpp:44:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   44 |   scanf("%d", state + i);
      |   ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4172 KB Output is correct
2 Correct 3 ms 4172 KB Output is correct
3 Correct 3 ms 4172 KB Output is correct
4 Correct 3 ms 4172 KB Output is correct
5 Correct 3 ms 4172 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4172 KB Output is correct
2 Correct 3 ms 4172 KB Output is correct
3 Correct 3 ms 4172 KB Output is correct
4 Correct 3 ms 4172 KB Output is correct
5 Correct 3 ms 4172 KB Output is correct
6 Correct 3 ms 4180 KB Output is correct
7 Correct 3 ms 4172 KB Output is correct
8 Correct 3 ms 4148 KB Output is correct
9 Correct 3 ms 4172 KB Output is correct
10 Correct 3 ms 4172 KB Output is correct
11 Correct 3 ms 4172 KB Output is correct
12 Correct 3 ms 4172 KB Output is correct
13 Correct 3 ms 4172 KB Output is correct
14 Correct 3 ms 4172 KB Output is correct
15 Correct 3 ms 4172 KB Output is correct
16 Correct 3 ms 4172 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 72 ms 23172 KB Output is correct
2 Correct 69 ms 22948 KB Output is correct
3 Correct 73 ms 23304 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 75 ms 23224 KB Output is correct
2 Correct 70 ms 22960 KB Output is correct
3 Correct 78 ms 23348 KB Output is correct
4 Correct 62 ms 8644 KB Output is correct
5 Correct 72 ms 9104 KB Output is correct
6 Correct 75 ms 9248 KB Output is correct
7 Correct 3 ms 4172 KB Output is correct
8 Correct 23 ms 5960 KB Output is correct
9 Correct 71 ms 9312 KB Output is correct
10 Correct 76 ms 9440 KB Output is correct
11 Correct 74 ms 10232 KB Output is correct
12 Correct 75 ms 10564 KB Output is correct
13 Correct 66 ms 8904 KB Output is correct
14 Correct 100 ms 9196 KB Output is correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4172 KB Output is correct
2 Correct 3 ms 4172 KB Output is correct
3 Correct 3 ms 4172 KB Output is correct
4 Correct 3 ms 4172 KB Output is correct
5 Correct 3 ms 4172 KB Output is correct
6 Correct 3 ms 4180 KB Output is correct
7 Correct 3 ms 4172 KB Output is correct
8 Correct 3 ms 4148 KB Output is correct
9 Correct 3 ms 4172 KB Output is correct
10 Correct 3 ms 4172 KB Output is correct
11 Correct 3 ms 4172 KB Output is correct
12 Correct 3 ms 4172 KB Output is correct
13 Correct 3 ms 4172 KB Output is correct
14 Correct 3 ms 4172 KB Output is correct
15 Correct 3 ms 4172 KB Output is correct
16 Correct 3 ms 4172 KB Output is correct
17 Correct 72 ms 23172 KB Output is correct
18 Correct 69 ms 22948 KB Output is correct
19 Correct 73 ms 23304 KB Output is correct
20 Correct 75 ms 23224 KB Output is correct
21 Correct 70 ms 22960 KB Output is correct
22 Correct 78 ms 23348 KB Output is correct
23 Correct 62 ms 8644 KB Output is correct
24 Correct 72 ms 9104 KB Output is correct
25 Correct 75 ms 9248 KB Output is correct
26 Correct 3 ms 4172 KB Output is correct
27 Correct 23 ms 5960 KB Output is correct
28 Correct 71 ms 9312 KB Output is correct
29 Correct 76 ms 9440 KB Output is correct
30 Correct 74 ms 10232 KB Output is correct
31 Correct 75 ms 10564 KB Output is correct
32 Correct 66 ms 8904 KB Output is correct
33 Correct 100 ms 9196 KB Output is correct
34 Correct 3 ms 4172 KB Output is correct
35 Correct 3 ms 4172 KB Output is correct
36 Correct 3 ms 4172 KB Output is correct
37 Correct 3 ms 4172 KB Output is correct
38 Correct 3 ms 4172 KB Output is correct
39 Correct 3 ms 4172 KB Output is correct
40 Correct 3 ms 4172 KB Output is correct
41 Correct 3 ms 4172 KB Output is correct
42 Correct 4 ms 4172 KB Output is correct
43 Correct 3 ms 4172 KB Output is correct
44 Correct 3 ms 4172 KB Output is correct
45 Correct 90 ms 23264 KB Output is correct
46 Correct 82 ms 22980 KB Output is correct
47 Correct 74 ms 23304 KB Output is correct
48 Correct 62 ms 8736 KB Output is correct
49 Correct 70 ms 9092 KB Output is correct
50 Correct 75 ms 9272 KB Output is correct
51 Correct 3 ms 4224 KB Output is correct
52 Correct 22 ms 5956 KB Output is correct
53 Correct 77 ms 9296 KB Output is correct
54 Correct 79 ms 9436 KB Output is correct
55 Correct 71 ms 10308 KB Output is correct
56 Correct 73 ms 10536 KB Output is correct
57 Correct 71 ms 8984 KB Output is correct
58 Correct 75 ms 9160 KB Output is correct
59 Correct 22 ms 5936 KB Output is correct
60 Correct 63 ms 8796 KB Output is correct
61 Correct 72 ms 9244 KB Output is correct
62 Correct 75 ms 9412 KB Output is correct
63 Correct 72 ms 9332 KB Output is correct
64 Correct 78 ms 9408 KB Output is correct
65 Correct 64 ms 9716 KB Output is correct
66 Correct 63 ms 9744 KB Output is correct
67 Correct 54 ms 9660 KB Output is correct
68 Correct 55 ms 9572 KB Output is correct
69 Correct 56 ms 9660 KB Output is correct
70 Correct 55 ms 9676 KB Output is correct