# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
103718 | 2019-04-02T08:51:52 Z | E869120 | Mousetrap (CEOI17_mousetrap) | C++14 | 7 ms | 1280 KB |
#include <iostream> #include <vector> #include <algorithm> using namespace std; #pragma warning (disable: 4996) const int MAX_N = (1 << 12); int N, A, B, E[MAX_N], F[MAX_N], dist[MAX_N], dp[MAX_N][22], val[MAX_N], pl[MAX_N]; bool used[MAX_N]; vector<int>X[MAX_N], Z[MAX_N], lis[MAX_N]; void dfs1(int pos, int dep) { used[pos] = true; dist[pos] = dep; for (int i = 0; i < X[pos].size(); i++) { if (used[X[pos][i]] == true) continue; dp[X[pos][i]][0] = pos; dfs1(X[pos][i], dep + 1); } } int prevs(int pos, int x) { for (int i = 21; i >= 0; i--) { if (x >= (1 << i)) { pos = dp[pos][i]; x -= (1 << i); } } return pos; } int lca(int u, int v) { if (dist[u] > dist[v]) swap(u, v); v = prevs(v, dist[v] - dist[u]); if (u == v) return u; for (int i = 21; i >= 0; i--) { if (dp[u][i] != dp[v][i]) { u = dp[u][i]; v = dp[v][i]; } } return dp[u][0]; } int ret[MAX_N]; int dfs2(int pos) { used[pos] = true; if (X[pos].size() <= 1) { return 0; } if (X[pos].size() == 2) { return 1; } vector<int>vec; for (int i = 0; i < Z[pos].size(); i++) { if (used[Z[pos][i]] == true) continue; vec.push_back(dfs2(Z[pos][i])); } sort(vec.begin(), vec.end()); int V = vec[vec.size() - 2]; return V + vec.size(); } int main() { scanf("%d%d%d", &N, &A, &B); for (int i = 1; i <= N - 1; i++) { scanf("%d%d", &E[i], &F[i]); X[E[i]].push_back(F[i]); X[F[i]].push_back(E[i]); } dfs1(B, 0); for (int i = 0; i < 21; i++) { for (int j = 1; j <= N; j++) dp[j][i + 1] = dp[dp[j][i]][i]; } for (int i = 1; i <= N; i++) { int v = lca(A, i); val[i] = dist[v]; if (v == i) pl[dist[v]] = i; else lis[dist[v]].push_back(i); } int FinalAns = 0; for (int i = 1; i <= N; i++) used[i] = false; for (int i = 0; i < dist[A]; i++) { for (int j = 0; j < lis[i].size(); j++) { int u = lis[i][j], v = dp[u][0]; Z[u].push_back(v); Z[v].push_back(u); } int rem = dfs2(pl[i]); if (Z[pl[i]].size() == 1) rem = 1; if (Z[pl[i]].size() <= 0) rem = 0; FinalAns += rem; } cout << FinalAns << endl; return 0; }
Compilation message
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 4 ms | 640 KB | Output is correct |
2 | Correct | 3 ms | 640 KB | Output is correct |
3 | Correct | 2 ms | 636 KB | Output is correct |
4 | Correct | 2 ms | 640 KB | Output is correct |
5 | Incorrect | 2 ms | 640 KB | Output isn't correct |
6 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Incorrect | 7 ms | 1280 KB | Output isn't correct |
2 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 4 ms | 640 KB | Output is correct |
2 | Correct | 3 ms | 640 KB | Output is correct |
3 | Correct | 2 ms | 636 KB | Output is correct |
4 | Correct | 2 ms | 640 KB | Output is correct |
5 | Incorrect | 2 ms | 640 KB | Output isn't correct |
6 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 4 ms | 640 KB | Output is correct |
2 | Correct | 3 ms | 640 KB | Output is correct |
3 | Correct | 2 ms | 636 KB | Output is correct |
4 | Correct | 2 ms | 640 KB | Output is correct |
5 | Incorrect | 2 ms | 640 KB | Output isn't correct |
6 | Halted | 0 ms | 0 KB | - |