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QOJ

ID	Problem	Submitter	Result	Time	Memory	Language	File size	Submit time	Judge time
#416266	#8720. BFS 序 0	podys	WA	301ms	90664kb	C++20	1.8kb	2024-05-21 18:37:31	2024-05-21 18:37:31

Judging History

你现在查看的是最新测评结果

[2024-05-21 18:37:31]
评测

测评结果：WA
用时：301ms
内存：90664kb

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[2024-05-21 18:37:31]
提交

answer

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl "\n"
int fa[300005][20],dep[300005],a[500005],in[300005];
vector<int> to[300005];
set<int> test[300005],node;
bool flag;
void dfs(int root,int f){
    dep[root]=dep[f]+1;
    // for (int i=1;i<=19;i++) {
    //     fa[root][i] = fa[fa[root][i-1]][i-1];
    // }
    for (auto x:to[root]) {
        if (x == f) continue;
        dfs(x, root);
    }
}
void lca(int x, int y) {
    for (int j = 19; j >= 0; j--) {
        if (fa[x][j] != fa[y][j]) {
            x = fa[x][j];
            y = fa[y][j];
        }
    }
    test[x].insert(y);
    in[y]++;
    node.insert(x);node.insert(y);
}
bool solve(){
    node.clear();
    flag=1;
    int n;
    cin>>n;
    
    for(int i=0;i<n;i++) cin>>a[i];
    for(int i=1;i<n;i++){
        if(a[i-1]==a[i]) flag=0;
        if(dep[a[i-1]]>dep[a[i]]) flag=0;
    }
    if(!flag) return 0;
    
    for(int i=1;i<n;i++){
        if(dep[a[i-1]]<dep[a[i]]) continue;
        lca(a[i-1],a[i]);
    }
    deque<int> que;
    
    for(auto x:node){
        if(!in[x]) que.push_back(x);
    }
    while(!que.empty()){
        int x = que.front();
        que.pop_front();
        for (auto y : test[x]) {
            in[y]--;
            if (!in[y]) que.push_back(y);
        }
    }
    for(auto x:node){
        if(in[x]) flag=0,in[x]=0,test[x].clear();
    }
    
    return flag;
}
signed main(){
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int n,q;
    cin>>n;
    for(int i=2;i<=n;i++){
        cin>>fa[i][0];
        to[fa[i][0]].push_back(i);
        for (int j=1;j<=19;j++) {
            fa[i][j] = fa[fa[i][j-1]][j-1];
        }
    }
    dfs(1,0);
    cin>>q;
    while(q--) cout<<(solve()?"Yes":"No")<<endl;
    return 0;
}

Source code, Language: C++20

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100

Accepted

time: 0ms

memory: 25340kb

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: 301ms

memory: 90664kb

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
No
No
No
No
Yes
Yes
No
No
No
No
No
No
No
No
Yes
No
No
No
No
No
Yes
No
No
No
Yes
No
No
No
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
Yes
Yes
No
No
Yes
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
Yes
No
No
No
Yes
No
No
Yes
No
No
No
No
Yes
No
No
No
Yes
No
No
No
No
N...

result:

wrong answer expected YES, found NO [3rd token]