Submission #936130

#	Time	Username	Problem	Language	Result	Execution time	Memory
936130		vjudge1	Rigged Roads (NOI19_riggedroads)	C++17	100 / 100	440 ms	96160 KiB

riggedroads

#include<bits/stdc++.h>
#define pb push_back
#define pli pair<int,int>
#define fi first
#define se second
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL);
using namespace std;
using ll=long long;
const ll maxn=3e5+10;
const ll inf=1e18;
const ll mod=1e9+7;
bool ins[maxn];
ll lab[maxn],top[maxn],P[maxn][20];
ll findset(ll x)
{
    return lab[x]<0?x:lab[x]=findset(lab[x]);
}
vector<pli>g[maxn];
ll h[maxn];
void unite(ll u,ll v)
{
    u=findset(u);
    v=findset(v);
    if(u==v) return;
    if(lab[u]>lab[v]) swap(u,v);
    lab[u]+=lab[v];
    lab[v]=u;
    if(h[top[u]]>h[top[v]]) top[u]=top[v];
}
ll idx[maxn];
void dfs(ll u,ll p)
{
    P[u][0]=p;
    for(int i=1;i<=18;i++) P[u][i]=P[P[u][i-1]][i-1];
    for(auto [v,id]:g[u])
    {
        if(v!=p)
        {
            h[v]=h[u]+1;
            idx[v]=id;
            dfs(v,u);
        }
    }
}
void update(ll u)
{
    ins[u]=true;
    top[u]=u;
    for(auto [v,id]:g[u])
    {
        if(ins[v]==true) unite(u,v);
    }
}
ll par[maxn];
vector<pli>get(ll u,ll p)
{
    vector<pli>ans;
    while(h[u]>h[p])
    {
        if(ins[u]==true)
        {
            u=top[findset(u)];
            u=P[u][0];
        }
        else
        {
            ans.pb({u,idx[u]});
            u=P[u][0];
        }
    }
    return ans;
}
ll n,e,x[maxn],y[maxn];
bool in[maxn];
ll ans[maxn];
ll lca(ll u,ll v)
{
    if(h[u]<h[v]) swap(u,v);
    for(int i=18;i>=0;i--) if(h[u]-(1<<i)>=h[v]) u=P[u][i];
    if(u==v) return u;
    for(int i=18;i>=0;i--) if(P[u][i]!=P[v][i]) u=P[u][i],v=P[v][i];
    return P[u][0];
}
bool cmp(pli x,pli y)
{
    return x.se<y.se;
}
void solve()
{
    cin >> n >> e;
    for(int i=1;i<=n;i++) lab[i]=-1;
    for(int i=1;i<=e;i++)
    {
        cin >> x[i] >> y[i];
        in[i]=false;
    }
    for(int i=1;i<n;i++)
    {
        ll id;
        cin >> id;
        in[id]=true;
        g[x[id]].pb({y[id],id});
        g[y[id]].pb({x[id],id});
    }
    dfs(1,0);
    ll dien=0;
    for(int i=1;i<=e;i++)
    {
        if(ans[i]>0) continue;
        if(in[i]==false)
        {
            ll u=x[i];
            ll v=y[i];
            ll c=lca(u,v);
            vector<pli>cc=get(u,c);
            vector<pli>vc=get(v,c);
            for(auto zz:vc) cc.pb(zz);
            sort(cc.begin(),cc.end(),cmp);
            for(auto zz:cc)
            {
                update(zz.fi);
                ans[zz.se]=++dien;
            }
            ans[i]=++dien;
        }
        else
        {
            ll u=x[i];
            ll v=y[i];
            if(h[u]<h[v]) swap(u,v);
            update(u);
            ans[i]=++dien;
        }
    }
    for(int i=1;i<=e;i++)
    {
        cout << ans[i]<<' ';
    }
}
int main()
{
    fastio
    //freopen(TASKNAME".INP","r",stdin);
    //freopen(TASKNAME".OUT","w",stdout);
    solve();
}

• Subtask 1: 8 / 8
• Subtask 2: 19 / 19
• Subtask 3: 9 / 9
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 12 / 12
• Subtask 7: 32 / 32