Submission #403625

#	Time	Username	Problem	Language	Result	Execution time	Memory
403625		zaneyu	족보 (KOI18_family)	C++14	100 / 100	300 ms	48892 KiB

family

/*input
7 8 4

7 7 6 6 0 5 5

6 7 7 8 0 5 5 5
*/
#include<bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0;i<n;i++)
#define REP1(i,n) for(int i=1;i<=n;i++)
#define ll long long
#define pii pair<int,int> 
#define pb push_back
#define ALL(x) x.begin(),x.end()
#define f first
#define s second
#define sz(x) (int)x.size()
const int maxn=3e5+5;
vector<int> v[maxn],v2[maxn];
int sz[maxn],sz2[maxn];
int id[maxn],id2[maxn];
int k;
void dfs(int u){
    if(u<k) id[u]=u,sz[u]=1;
    for(int x:v[u]){
        dfs(x);
        id[u]=id[x];
        sz[u]+=sz[x];
    }
}
void dfs2(int u){
    if(u<k) id2[u]=u,sz2[u]=1;
    for(int x:v2[u]){
        dfs2(x);
        id2[u]=id2[x];
        sz2[u]+=sz2[x];
    }  
}
int par[maxn],rank1[maxn];
int find(int u){
    if(par[u]==u) return u;
    return par[u]=find(par[u]);
}
void merge(int a,int b){
    a=find(a),b=find(b);
    if(a==b) return;
    par[a]=b;
    rank1[b]+=rank1[a];
}
int main(){
    ios::sync_with_stdio(false),cin.tie(0);
    int n,m;
    cin>>n>>m>>k;
    int r1,r2;
    REP(i,n){
        int x;
        cin>>x;
        --x;
        if(x!=-1) v[x].pb(i);
        else r1=i;
    }
    REP(i,m){
        int x;
        cin>>x;
        --x;
        if(x!=-1) v2[x].pb(i);
        else r2=i;
    }
    dfs(r1),dfs2(r2);
    vector<pii> va,vb;
    REP(i,n) if(sz(v[i])>1){
        va.pb({sz[i],i});
    }
    REP(i,m) if(sz(v2[i])>1){
        vb.pb({sz2[i],i});
    }
    sort(ALL(va)),sort(ALL(vb));
    int p=0;
    REP(i,k) par[i]=i,rank1[i]=1;
    REP(i,sz(va)){
        while(p<sz(vb) and vb[p].f<=va[i].f){
            for(auto x:v2[vb[p].s]) merge(id2[x],id2[vb[p].s]);
            ++p;
        }
        for(auto x:v[va[i].s]) merge(id[x],id[va[i].s]);
        if(rank1[find(id[va[i].s])]!=va[i].f){
            cout<<"NO\n";
            return 0;
        }
    }
    cout<<"YES\n";
}

Compilation message (stderr)

family.cpp: In function 'int main()':
family.cpp:70:17: warning: 'r2' may be used uninitialized in this function [-Wmaybe-uninitialized]
   70 |     dfs(r1),dfs2(r2);
      |             ~~~~^~~~
family.cpp:70:8: warning: 'r1' may be used uninitialized in this function [-Wmaybe-uninitialized]
   70 |     dfs(r1),dfs2(r2);
      |     ~~~^~~~

• Subtask 1: 17 / 17
• Subtask 2: 27 / 27
• Subtask 3: 15 / 15
• Subtask 4: 41 / 41