/**
* author: wxhtzdy
* created: 11.08.2022 18:52:59
**/
#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, k;
cin >> n >> k;
vector<vector<int>> g(n);
for (int i = 0; i < n - 1; i++) {
int u, v;
cin >> u >> v;
--u; --v;
g[u].push_back(v);
g[v].push_back(u);
}
vector<int> dep(n);
vector<int> dfn(n);
vector<int> dfo(n);
int T = 0;
function<void(int, int)> Dfs = [&](int v, int pr) {
dfn[v] = ++T;
for (int u : g[v]) {
if (u == pr) {
continue;
}
dep[u] = dep[v] + 1;
Dfs(u, v);
}
dfo[v] = ++T;
};
Dfs(0, 0);
if (*max_element(dep.begin(), dep.end()) < k) {
cout << "DA" << '\n';
return 0;
}
vector<vector<int>> at(n);
for (int i = 0; i < n; i++) {
at[dep[i]].push_back(i);
}
for (int i = 0; i < n; i++) {
sort(at[i].begin(), at[i].end(), [&](int u, int v) {
return dfn[u] < dfn[v];
});
}
auto isPar = [&](int v, int u) {
return dfn[v] <= dfn[u] && dfo[u] <= dfo[v];
};
vector<vector<vector<int>>> can(n, vector<vector<int>>(n, vector<int>(n, -1)));
function<bool(int, int, int)> Solve = [&](int l, int r, int dep) {
if (can[l][r][dep] != -1) {
return can[l][r][dep] == 1;
}
can[l][r][dep] = 0;
for (int v : at[dep]) {
int L = 0, R = 0;
{
int low = 0, high = at[k].size() - 1;
while (low <= high) {
int mid = low + high >> 1;
if (isPar(v, at[k][mid])) {
L = mid;
high = mid - 1;
} else {
if (dfn[v] > dfn[at[k][mid]]) {
low = mid + 1;
} else {
high = mid - 1;
}
}
}
}
{
int low = 0, high = at[k].size() - 1;
while (low <= high) {
int mid = low + high >> 1;
if (isPar(v, at[k][mid])) {
R = mid;
low = mid + 1;
} else {
if (dfn[v] > dfn[at[k][mid]]) {
low = mid + 1;
} else {
high = mid - 1;
}
}
}
}
if (!isPar(v, at[k][L])) {
continue;
}
bool ok = true;
if (L > l) {
ok &= Solve(l, L - 1, dep + 1);
}
if (R < r) {
ok &= Solve(R + 1, r, dep + 1);
}
if (ok) {
can[l][r][dep] = 1;
}
}
return can[l][r][dep] == 1;
};
cout << (Solve(0, (int) at[k].size() - 1, 1) ? "DA" : "NE") << '\n';
return 0;
}
Compilation message
burza.cpp: In lambda function:
burza.cpp:65:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
65 | int mid = low + high >> 1;
| ~~~~^~~~~~
burza.cpp:81:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
81 | int mid = low + high >> 1;
| ~~~~^~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
60 ms |
123428 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
98 ms |
221392 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
99 ms |
229536 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
95 ms |
214436 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
98 ms |
201232 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
104 ms |
227116 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
115 ms |
237932 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
81 ms |
153624 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
52 ms |
89056 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
69 ms |
148300 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |