Submission #646012

#	Time	Username	Problem	Language	Result	Execution time	Memory
646012		victor_gao	Jail (JOI22_jail)	C++17	0 / 100	14 ms	9172 KiB

jail

//#pragma GCC optimize("Ofast,unroll-loops,O3")
//#pragma GCC optimize("avx,avx2,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,fma,tune=native")
#include<bits/stdc++.h>
//#include<bits/extc++.h>
//#pragma pack(1)
#define fast ios::sync_with_stdio(0); cin.tie(0);
#define int long long
#define pii pair<int,int>
#define x first
#define y second
#define N 120015
using namespace std;
//using namespace __gnu_pbds;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//typedef tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update> order_multiset;
//typedef tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> order_set;
int n,m,st[N],ed[N],fa[N],dep[N],dfn[N],dft=0,low[N],nscc=0;
bool ins[N];
stack<int>s;
pii pos[N];
vector<int>g[N],ng[N],scc[N];
void dfs(int p,int lp){
    fa[p]=lp;
    dep[p]=dep[lp]+1;
    for (auto i:g[p]){
        if (i!=lp) dfs(i,p);
    }
}
int LCA(int a,int b){
    while (a!=b){
        if (dep[a]>dep[b]) a=fa[a];
        else b=fa[b];
    }
    return a;
}
int find_first_start(int x,int lca){
    if (dep[x]<dep[lca]) return 0;
    while (x!=lca&&!st[x]) x=fa[x];
    if (st[x]) return st[x];
    else return 0;
}
int find_first_end(int x,int lca){
    if (dep[x]<dep[lca]) return 0;
    while (x!=lca&&!ed[x]) x=fa[x];
    if (ed[x]) return ed[x];
    else return 0;
}
void tarjan(int p){
    dfn[p]=low[p]=++dft;
    s.push(p); ins[p]=1;
    for (auto i:ng[p]){
        if (!dfn[i]){
            tarjan(i);
            low[p]=min(low[p],low[i]);
        }
        else if (ins[i]&&dfn[i]<dfn[p])
            low[p]=min(low[p],dfn[i]);
    }
    if (low[p]==dfn[p]){
        nscc++;
        for (int x=0;x!=p;s.pop()){
            x=s.top(); ins[x]=0;
            scc[nscc].push_back(x);
        }
    }
}
void reset(){
    nscc=0; dft=0;
    while (!s.empty()) s.pop();
    for (int i=0;i<=m+5;i++){
        fa[i]=0; dfn[i]=0; low[i]=0; st[i]=0; 
        dep[i]=0; ins[i]=0; ed[i]=0;
        ng[i].clear();
        scc[i].clear();
    }
    for (int i=0;i<=n+5;i++){
        g[i].clear();
    }
}
signed main(){
    fast
    int q; cin>>q;
    while (q--){
        reset();
        cin>>n;
        for (int i=1;i<n;i++){
            int a,b; cin>>a>>b;
            g[a].push_back(b);
            g[b].push_back(a);
        }
        dfs(1,0);
        cin>>m;
        for (int i=1;i<=m;i++){
            cin>>pos[i].x>>pos[i].y;
            st[pos[i].x]=i;
            ed[pos[i].y]=i;
        }
        for (int i=1;i<=m;i++){
            int lca=LCA(pos[i].x,pos[i].y);
            int f=find_first_start(fa[pos[i].x],lca);
            if (f){
                ng[f].push_back(i);
            }
            f=find_first_start(pos[i].y,lca);
            if (f){
                ng[f].push_back(i);
            }
            int d=find_first_end(pos[i].x,lca);
            if (d){
                ng[i].push_back(d);
            }
            d=find_first_end(fa[pos[i].y],lca);
            if (d){
                ng[i].push_back(d);
            }
        }
        for (int i=1;i<=m;i++){
            if (!dfn[i]) tarjan(i);
        }
        if (nscc==m) cout<<"Yes\n";
        else cout<<"No\n";
    }
}

• 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