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ID	Problem	Submitter	Result	Time	Memory	Language	File size	Submit time	Judge time
#416259	#8720. BFS 序 0	podys	WA	296ms	93376kb	C++20	2.2kb	2024-05-21 18:24:22	2024-05-21 18:24:23

Judging History

你现在查看的是最新测评结果

[2024-05-21 18:24:23]
评测

测评结果：WA
用时：296ms
内存：93376kb

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[2024-05-21 18:24:22]
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[500005];
vector<int> to[300005];
set<int> test[300005];
set<int> node;
bool flag;
void dfs(int root,int f){
    fa[root][0]=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);
    }
}
int lk(int x, int y) {
	for (int j = 19; j >= 0; j--)
		if (dep[fa[x][j]] > dep[y]) x = fa[x][j];
	return x;
}

int 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];
        }
    }
    return fa[x][0];
}

// 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;
        int lc = lca(a[i-1],a[i]);
        int u = lk(a[i-1], lc), v = lk(a[i], lc);
        test[u].insert(v);
        in[v]++;
        node.insert(u);node.insert(v);
    }
    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);
    }
    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: 23908kb

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: 296ms

memory: 93376kb

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]