제출 #768601

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
768601		bachhoangxuan	Mergers (JOI19_mergers)	C++17	100 / 100	1069 ms	196260 KiB

mergers

// Judges with GCC >= 12 only needs Ofast
// #pragma GCC optimize("O3,no-stack-protector,fast-math,unroll-loops,tree-vectorize")
// MLE optimization
// #pragma GCC optimize("conserve-stack")
// Old judges
// #pragma GCC target("sse4.2,popcnt,lzcnt,abm,mmx,fma,bmi,bmi2")
// New judges. Test with assert(__builtin_cpu_supports("avx2"));
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
// Atcoder
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma")
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
- insert(x),erase(x)
- find_by_order(k): return iterator to the k-th smallest element
- order_of_key(x): the number of elements that are strictly smaller
*/
#include<bits/stdc++.h>
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
uniform_real_distribution<> pp(0.0,1.0);
//#define int long long
#define ld long double
#define pii pair<int,int>
#define piii pair<pii,int>
#define mpp make_pair
#define fi first
#define se second
//const int inf=1e18;
const int mod=1e9+7;
const int maxn=500005;
const int bl=650;
const int maxs=655;
const int maxm=200005;
const int maxq=500005;
const int maxl=20;
const int maxa=250000;
const int root=3;
/*
int power(int a,int n){
    int res=1;
    while(n){
        if(n&1) res=res*a%mod;
        a=a*a%mod;n>>=1;
    }
    return res;
}
const int iroot=power(3,mod-2);
*/
const int base=101;
namespace Tree{
    vector<vector<int>> edge,Min;
    vector<int> lg2,dep,L,R;
    int pos;
    int cmp(int u,int v){
        return (dep[u]<dep[v]?u:v);
    }
    int lca(int u,int v){
        u=L[u];v=L[v];
        if(u>v) swap(u,v);
        int p=lg2[v-u+1];
        return cmp(Min[u][p],Min[v-(1<<p)+1][p]);
    }
    int dist(int u,int v){
        return dep[u]+dep[v]-2*dep[lca(u,v)];
    }
    void dfs(int u,int p){
        L[u]=++pos;Min[pos][0]=u;
        dep[u]=dep[p]+1;
        for(int v:edge[u]){
            if(v==p) continue;
            dfs(v,u);Min[++pos][0]=u;
        }
        R[u]=pos;
    }
    void init(int n){
        lg2.assign(2*n+1,0);
        dep.assign(n+1,0);
        L.assign(n+1,0);
        R.assign(n+1,0);
        edge.resize(n+1);
        Min.assign(2*n+1,vector<int>(maxl,0));
    }
    void build(int n){
        init(n);
        for(int i=1;i<n;i++){
            int u,v;cin >> u >> v;
            edge[u].push_back(v);
            edge[v].push_back(u);
        }
        dfs(1,0);
        for(int i=2;i<=pos;i++) lg2[i]=lg2[i/2]+1;
        for(int i=1;i<20;i++){
            for(int j=1;j<=(pos-(1<<i)+1);j++) Min[j][i]=cmp(Min[j][i-1],Min[j+(1<<(i-1))][i-1]);
        }
    }
}
int num[maxn],p[maxn],par[maxn],cnt[maxn];
int findpar(int u){
    if(u!=par[u]) return par[u]=findpar(par[u]);
    return u;
}
void unions(int u,int v){
    u=findpar(u);v=findpar(v);
    if(u!=v) par[v]=u;
}
void add(int u,int v){
    num[u]++;num[v]++;
    num[Tree::lca(u,v)]-=2;
}
void dfs(int u,int p){
    for(int v:Tree::edge[u]){
        if(v==p) continue;
        dfs(v,u);num[u]+=num[v];
    }
    if(num[u]>=1 && p) unions(u,p);
}
void dfs2(int u,int p){
    if(num[u]==0 && p){
        cnt[findpar(u)]++;
        cnt[findpar(p)]++;
    }
    for(int v:Tree::edge[u]){
        if(v==p) continue;
        dfs2(v,u);
    }
}
void solve(){
    int n,k;cin >> n >> k;
    for(int i=1;i<=n;i++) par[i]=i;
    Tree::build(n);
    for(int i=1;i<=n;i++){
        int s;cin >> s;
        if(p[s]) add(i,p[s]);
        p[s]=i;
    }
    dfs(1,0);dfs2(1,0);
    int leaf=0;
    for(int i=1;i<=n;i++) leaf+=(cnt[i]==1);
    cout << (leaf+1)/2 << '\n';
}
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    int test=1;//cin >> test;
    while(test--) solve();
}

• Subtask 1: 10 / 10
• Subtask 2: 24 / 24
• Subtask 3: 14 / 14
• Subtask 4: 22 / 22
• Subtask 5: 30 / 30