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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#423421 | #8720. BFS 序 0 | Cipherxzc | WA | 195ms | 46484kb | C++20 | 2.2kb | 2024-05-28 00:12:15 | 2024-05-28 00:12:16 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
inline int lg(int x){
return 31 - __builtin_clz(x);
}
const int N = 3e5 + 5, M = 5e5 + 5;
int n, q, root = 1, dep[N], m, a[M];
vector<int> e[N], e2[N];
map<int, bool> vis;
bool flag;
inline void add(int u, int v){
e[u].push_back(v);
}
inline void add2(int u, int v){
//cout << u << ' ' << v << endl;
e[u].push_back(v);
vis[u] = vis[v] = false;
}
namespace LCA{
int fa[20][N];
void dfs(int p){
for (int q : e[p]){
if (q == fa[0][p]){
continue;
}
dep[q] = dep[p] + 1;
fa[0][q] = p;
dfs(q);
}
}
void init(){
dfs(root);
for (int j = 1; j <= lg(n - 1); j++){
for (int i = 1; i <= n; i++){
fa[j][i] = fa[j - 1][fa[j - 1][i]];
}
}
}
int lca(int u, int v){
if (dep[u] < dep[v]){
swap(u, v);
}
while (dep[u] - dep[v]){
u = fa[lg(dep[u] - dep[v])][u];
}
if (u == v){
return u;
}
for (int i = lg(dep[u]); i >= 0; i--){
if (fa[i][u] != fa[i][v]){
u = fa[i][u]; v = fa[i][v];
}
}
return fa[0][u];
}
inline int get(int u, int v){
while (dep[u] - dep[v] > 1){
u = fa[lg(dep[u] - dep[v] - 1)][u];
}
return u;
}
}
void dfs(int p){
vis[p] = true;
for (int q : e2[p]){
if (vis[q]){
flag = false;
break;
}else{
dfs(q);
}
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
cin >> n;
for (int i = 2, fa; i <= n; i++){
cin >> fa;
add(fa, i);
}
LCA::init();
cin >> q;
while (q--){
for (auto [x, y] : vis){
e2[x].clear();
}
vis.clear();
cin >> m;
for (int i = 1; i <= m; i++){
cin >> a[i];
}
flag = true;
for (int i = 2; i <= m && flag; i++){
int u = a[i - 1], v = a[i];
if (dep[u] > dep[v]){
//cout << "! " << u << ' ' << v << endl;
flag = false;
}else if (dep[u] == dep[v]){
int w = LCA::lca(u, v);
int x = LCA::get(u, w), y = LCA::get(v, w);
add2(x, y);
}
}
if (flag){
for (auto [x, y] : vis){
if (!y){
dfs(y);
}
}
}
if (flag){
cout << "Yes" << endl;
}else{
cout << "No" << endl;
}
}
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 2ms
memory: 9872kb
input:
6 1 1 3 2 4 10 4 3 6 2 5 1 4 3 2 4 5 5 2 5 4 6 3 3 1 4 2 3 5 6 3 5 4 5 2 6 1 4 4 3 2 5 4 4 6 2 3 3 3 2 6
output:
No Yes Yes No No No No No No Yes
result:
ok 10 token(s): yes count is 3, no count is 7
Test #2:
score: -100
Wrong Answer
time: 195ms
memory: 46484kb
input:
300000 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1...
output:
Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes ...
result:
wrong answer expected NO, found YES [1st token]