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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#661727 | #8551. DFS Order 5 | LeNcyer | WA | 39ms | 9908kb | C++17 | 4.0kb | 2024-10-20 17:47:36 | 2024-10-20 17:47:37 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
using ll = long long;
const int N = 1e5 + 10;
const int lim = 20;
class Segment{
private:
struct Node {
int val, tag;
} node[N << 2];
public:
void push_up (int p) {
node[p].val = node[p << 1].val | node[p << 1 | 1].val;
}
void build (int s, int t, int p = 1) {
node[p].tag = -1;
if (s == t) {
node[p].val = 0;
return;
}
int mid = (s + t) >> 1;
build(s, mid, p << 1);
build(mid + 1, t, p << 1 | 1);
push_up(p);
}
void push_down (int p) {
if (node[p].tag != -1) {
node[p << 1].tag = node[p << 1].val = node[p].tag;
node[p << 1 | 1].tag = node[p << 1 | 1].val = node[p].tag;
node[p].tag = -1;
}
}
void update (int l, int r, int v, int s, int t, int p = 1) {
if (l <= s && t <= r) {
node[p].val = v;
node[p].tag = v;
return;
}
push_down(p);
int mid = (s + t) >> 1;
if (l <= mid) update(l, r, v, s, mid, p << 1);
if (mid < r) update(l, r, v, mid + 1, t, p << 1 | 1);
push_up(p);
}
int query (int l, int r, int s, int t, int p = 1) {
if (l <= s && t <= r) return node[p].val;
push_down(p);
int mid = (s + t) >> 1;
int res = 0;
if (l <= mid) res = query(l, r, s, mid, p << 1);
if (mid < r) res |= query(l, r, mid + 1, t, p << 1 | 1);
push_up(p);
return res;
}
};
Segment seg;
int n, q;
vector<int> t[N];
int dep[N], f[N][lim];
int sz[N], dfn[N], hs[N], tp[N], totdfn = 0;
void dfs (int x, int fa) {
f[x][0] = fa;
dep[x] = dep[fa] + 1;
sz[x] = 1;
for (int i = 1; i < lim; i ++) {
f[x][i] = f[f[x][i - 1]][i - 1];
}
hs[x] = 0;
for (auto y: t[x]) {
if (y == fa) continue;
dfs(y, x);
sz[x] += sz[y];
if(sz[y] > sz[hs[x]]) hs[x] = y;
}
}
void dfs2 (int x, int fa, int top) {
dfn[x] = ++ totdfn;
tp[x] = top;
if (hs[x]) dfs2(hs[x], x, top);
for (auto y: t[x]) {
if (y == fa || y == hs[x]) continue;
dfs2(y, x, y);
}
}
int get (int x, int len) {
int cur = x;
for (int i = 0; i < lim; i ++) {
if ((len >> i) & 1) cur = f[cur][i];
}
return cur;
}
int get_lca (int x, int y) {
for (int i = lim - 1; i >= 0; i --) {
if (dep[f[x][i]] >= dep[y]) x = f[x][i];
if (dep[f[y][i]] >= dep[x]) y = f[y][i];
}
if (x == y) return x;
for (int i = lim - 1; i >= 0; i --) {
if (f[x][i] != f[y][i]) {
x = f[x][i];
y = f[y][i];
}
}
return f[x][0];
}
int cal (int x, int y) {
// cout << "cal: " << x << ' ' << y << endl;
int res = 0;
while (dep[x] >= dep[y]) {
int l = dfn[tp[x]], r = dfn[x];
if (dep[y] > dep[tp[x]]) l = dfn[y];
res |= seg.query(l, r, 1, n);
if (res) return res;
x = f[tp[x]][0];
}
return res;
}
void col (int x, int y) {
while (dep[x] >= dep[y]) {
int l = dfn[tp[x]], r = dfn[x];
if (dep[y] > dep[tp[x]]) l = dfn[y];
seg.update(l, r, 1, 1, n);
x = f[tp[x]][0];
}
return;
}
void init () {
cin >> n >> q;
for (int i = 1; i < n; i ++) {
int u, v;
cin >> u >> v;
t[u].push_back(v);
t[v].push_back(u);
}
}
int a[N], pos[N];
void solve() {
init();
dfs(1, 0);
dfs2(1, 0, 1);
seg.build(1, n);
// for (int i = 1; i <= n; i ++) {
// cout << i << ' ' << hs[i] << ' ' << tp[i] << endl;
// }
// cout << "debug\n";
while (q --) {
int k;
cin >> k;
for (int i = 1; i <= k; i ++) {
cin >> a[i];
pos[a[i]] = i;
}
seg.update(1, n, 0, 1, n);
bool ok = 1;
for (int i = 2; i <= k; i ++) {
int r = min(k, i + sz[a[i]] - 1);
if (get_lca(a[i], a[r]) != a[i]) {
ok = 0;
break;
}
int fa = f[a[i]][0];
if (fa == a[i - 1]) continue;
int lca = get_lca(a[i - 1], a[i]);
if (fa != lca) {
ok = 0;
break;
}
int u = a[i - 1], v = get(a[i - 1], dep[a[i - 1]] - dep[fa] - 1);
if (cal(u, v) || cal(a[i], a[i])) {
ok = 0;
break;
}
col(u, v);
}
if (ok) cout << "Yes\n";
else cout << "No\n";
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int _ = 1;
// cin >> _;
while (_--)
solve();
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 9908kb
input:
6 7 1 2 1 3 2 4 3 5 2 6 2 4 1 2 4 2 2 4 3 2 4 4 2 4 5 2 4 6 6 1 2 6 4 3 5
output:
No No Yes No No Yes Yes
result:
ok 7 tokens
Test #2:
score: -100
Wrong Answer
time: 39ms
memory: 9784kb
input:
10 100000 7 2 1 7 7 10 8 6 8 7 1 3 4 5 9 5 5 8 8 8 9 7 2 8 1 6 1 4 8 3 5 2 6 7 10 3 9 9 1 1 1 8 10 3 2 9 3 8 7 3 7 5 6 2 8 5 9 1 6 3 4 6 2 1 3 5 8 9 2 4 9 1 3 2 1 5 5 8 5 1 7 9 10 5 2 9 2 6 4 10 6 3 8 3 4 5 8 2 8 4 9 4 10 1 2 4 3 3 6 3 1 3 6 1 1 6 8 3 1 3 7 3 2 3 9 1 5 4 3 7 8 10 9 4 2 3 10 2 5 4 3 ...
output:
No No No Yes No No No No Yes No No No No No No Yes No No No No No No No No No No No No No Yes No Yes No No No No No No Yes No No No No No Yes Yes No No No No No No No No No No No No No No No No No No No No No No No No Yes No No Yes Yes No No No No Yes No No No No No No No No No No No No No No No No ...
result:
wrong answer 30th words differ - expected: 'No', found: 'Yes'