Submission #936226

#	Time	Username	Problem	Language	Result	Execution time	Memory
936226		vjudge1	Rigged Roads (NOI19_riggedroads)	C++14	100 / 100	378 ms	65728 KiB

riggedroads

#include<bits/stdc++.h>
using namespace std;
#define all(fl) fl.begin(),fl.end()
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define lb lower_bound
#define ub upper_bound
#define sz(a) (int)a.size()
#define pii pair<int,int>
#define pli pair<long long,int>
#define gcd __gcd
#define lcm(x,y) x*y/__gcd(x,y)
#define pil pair<int,long long>
const int maxn=3e5+9;
vector<pii>a[maxn];
int st[maxn][21],d[maxn];
pii pr[maxn];
void dfs(int u,int par){
for (auto v:a[u]){
if (v.fi==par)continue;
pr[v.fi]={u,v.se};
st[v.fi][0]=u;
for1(i,1,20)st[v.fi][i]=st[st[v.fi][i-1]][i-1];
d[v.fi]=d[u]+1;
dfs(v.fi,u);
}
}
pii b[maxn];
int lca(int u,int v){
if (d[u]<d[v])swap(u,v);
int k=d[u]-d[v];
for1(i,0,20)if (k>>i&1)u=st[u][i];
if (u==v)return u;
for2(i,20,0){
if (!st[u][i]||!st[v][i])continue;
if (st[u][i]!=st[v][i]){
u=st[u][i];
v=st[v][i];
}
}
return st[u][0];
}
bool use[maxn];
int ans[maxn];
int f[maxn];
int fs(int u){
if (f[u]<0)return u;
return f[u]=fs(f[u]);
}
void unite(int u,int v){
u=fs(u),v=fs(v);
if (u==v)return;
f[v]+=f[u];
f[u]=v;
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen("temp.INP","r",stdin);
    //freopen("temp.OUT","w",stdout);
    int n,m;
    cin>>n>>m;
    for1(i,1,m)cin>>b[i].fi>>b[i].se;
    for1(i,1,n)f[i]=-1;
    for1(i,1,n-1){
    int id;
    cin>>id;
    use[id]=1;
    a[b[id].fi].pb({b[id].se,id});
    a[b[id].se].pb({b[id].fi,id});
    }
    dfs(1,0);
    vector<int>perm;
    auto take=[&](int id){
    int u=b[id].fi,v=b[id].se,t=lca(u,v);
    vector<int>xd;
    while (fs(u)!=fs(t)){
    u=fs(u);
    xd.pb(pr[u].se);
    unite(u,pr[u].fi);
    u=fs(pr[u].fi);
    }
    while (fs(v)!=fs(t)){
    v=fs(v);
    xd.pb(pr[v].se);
    unite(v,pr[v].fi);
    v=fs(pr[v].fi);
    }
    sort(all(xd));
    for (auto v1:xd)perm.pb(v1);
    if (!use[id])perm.pb(id);
    };
    for1(i,1,m){
    take(i);
    }
    int cnt=0;
    for (auto v:perm)ans[v]=++cnt;
    for1(i,1,m)cout<<ans[i]<<" ";
}

• 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