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The 2nd Universal Cup Finals is coming! Check out our event page, schedule, and competition rules!
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#417715 | #8720. BFS 序 0 | Larunatrecy# | WA | 134ms | 50276kb | C++14 | 2.0kb | 2024-05-22 21:11:28 | 2024-05-22 21:11:28 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
template <typename T>inline void read(T &x)
{
x=0;char c=getchar();bool f=0;
for(;c<'0'||c>'9';c=getchar())f|=(c=='-');
for(;c>='0'&&c<='9';c=getchar())x=(x<<1)+(x<<3)+(c-'0');
x=(f?-x:x);
}
const int N = 5e5+7;
int fa[N][20],dep[N];
int n,m,q,seq[N];
vector<int> used;
vector<int> G[N];
int deg[N];
int lca(int x,int y)
{
if(dep[x]<dep[y])swap(x,y);
for(int k=19;k>=0;k--)
if(dep[fa[x][k]]>=dep[y])
x=fa[x][k];
if(x==y)return x;
for(int k=19;k>=0;k--)
if(fa[x][k]!=fa[y][k])
{
x=fa[x][k];
y=fa[y][k];
}
return fa[x][0];
}
int jump(int x,int y)
{
for(int k=19;k>=0;k--)
if(dep[fa[x][k]]>dep[y])
x=fa[x][k];
return x;
}
bool solve()
{
for(int x:used)deg[x]=0,G[x].clear();
used.clear();
for(int i=1;i+1<=m;i++)
{
int x=seq[i],y=seq[i+1];
if(dep[x]>dep[y])return 0;
if(x==y)return 0;
if(dep[x]!=dep[y])continue;
int o=lca(x,y);
x=jump(x,o);
y=jump(y,o);
G[x].push_back(y);
deg[y]++;
used.push_back(x);
used.push_back(y);
}
queue<int> que;
used.erase(unique(used.begin(),used.end()),used.end());
for(int x:used)
if(!deg[x])
{
que.push(x);
}
while(!que.empty())
{
int x=que.front();
que.pop();
for(int y:G[x])if(!(--deg[y]))
que.push(y);
}
for(int x:used)if(deg[x])return 0;
return 1;
}
int main()
{
read(n);
for(int i=2;i<=n;i++)
{
read(fa[i][0]);
dep[i]=dep[fa[i][0]]+1;
for(int k=1;fa[i][k-1];k++)
fa[i][k]=fa[fa[i][k-1]][k-1];
}
read(q);
while(q--)
{
read(m);
for(int i=1;i<=m;i++)read(seq[i]);
bool f=solve();
if(f)printf("YES\n");
else printf("NO\n");
}
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 21932kb
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: 134ms
memory: 50276kb
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:
NO YES NO NO NO NO NO NO NO NO YES YES NO YES NO YES YES YES NO NO NO NO NO NO NO YES NO NO NO NO YES YES NO NO NO YES NO NO NO NO NO NO NO YES NO YES NO YES NO NO NO NO NO YES YES NO NO YES NO NO NO NO NO YES YES NO NO NO NO NO NO NO NO YES NO NO NO YES NO NO YES NO NO YES NO YES NO NO NO YES NO NO...
result:
wrong answer expected YES, found NO [3rd token]