Submission #712922

#	Time	Username	Problem	Language	Result	Execution time	Memory
712922		lam	Jail (JOI22_jail)	C++14	0 / 100	2 ms	3156 KiB

jail

#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 2e4 + 10;
typedef pair<int,int> ii;
#define ff first
#define ss second
int n,m;
vector <int> adj[maxn];
int par[18][maxn];
int in[maxn],out[maxn],cnt;
bool dau[maxn];
vector <int> d;
ii num[maxn], a[maxn];
void dfs(int x, int p)
{
    par[0][x]=p;
    in[x]=++cnt;
    for (int i=1; i<=17; i++) par[i][x]=par[i-1][par[i-1][x]];
    for (int i:adj[x])
        if (i!=p)
            dfs(i,x);
    out[x]=cnt;
}
bool check(int u, int v)
{
    return in[u]<=in[v]&&out[v]<=out[u];
}
int lca(int u, int v)
{
    if (check(u,v)) return u;
    if (check(v,u)) return v;
    for (int i=17; i>=0; i--)
        if (!check(par[i][u],v)) u=par[i][u];
    return par[0][u];
}
void upd(int u, int v, int type)
{
//    int it=1;
    while (v!=u)
    {
//        it++; if (it==10) break;
//        cerr<<u<<' '<<v<<endl;
        if (type==1) num[v].ff++;
        else num[v].ss++;
        v=par[0][v];
    }
}
bool check_mid(int u, int v, int mid)
{
    return check(u,mid)&&check(mid,v);
}
bool check_path(int u, int v, int x, int y)
{
    /**
    u x y v
    **/
    int p=lca(u,v);
    if ((check_mid(p,u,x)||check_mid(p,v,x))&&(check_mid(p,u,y)||check_mid(p,v,y))) return 1;
    return 0;
}
void xuly()
{
    cin>>n;
    for (int i=1; i<=n; i++) adj[i].clear(), in[i]=out[i]=0, num[i]={0,0}; cnt=0;
    for (int i=1; i<n; i++)
    {
        int u,v; cin>>u>>v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    dfs(1,1);
    cin>>m; d.clear();
    for (int i=1; i<=m; i++) cin>>a[i].ff>>a[i].ss, d.push_back(i);
    do
    {
        for (int i=1; i<=m; i++) dau[a[i].ff] = 1;
        bool ccheck = 1;
        for (int i:d)
        {
            int u = a[i].ff; int v=a[i].ss;
            dau[u] = 0;
            int p=lca(u,v);
            while (u!=p)
            {
                if (dau[u]) ccheck = 0;
                u=par[0][u];
            }
            if (dau[p]) ccheck=0;
            while (v!=p)
            {
                if (dau[v]) ccheck=0;
                v=par[0][v];
            }
            dau[v] = 1;
            if (!ccheck) break;
        }
        if (!ccheck) continue;
        cout<<"Yes\n";
        return;
    }
    while (next_permutation(d.begin(),d.end()));
    cout<<"No\n";
}
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    int tt; cin>>tt;
    while (tt--) xuly();
}

Compilation message (stderr)

jail.cpp: In function 'void xuly()':
jail.cpp:64:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   64 |     for (int i=1; i<=n; i++) adj[i].clear(), in[i]=out[i]=0, num[i]={0,0}; cnt=0;
      |     ^~~
jail.cpp:64:76: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   64 |     for (int i=1; i<=n; i++) adj[i].clear(), in[i]=out[i]=0, num[i]={0,0}; cnt=0;
      |                                                                            ^~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 16
• Subtask 4: 0 / 28
• Subtask 5: 0 / 12
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23