제출 #1276650

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1276650		sasde	Mergers (JOI19_mergers)	C++20	100 / 100	531 ms	136672 KiB

mergers

#include<bits/stdc++.h>
using namespace std;
bool M1;
#define PI 3.14159265358979323846
#define sz(a) (int)a.size()
#define all(x) x.begin(),x.end()
#define ii pair<int,int>
#define iii pair<int,ii>
#define iv pair<ii,ii>
#define se second
#define fi first
#define ffi fi.fi
#define sfi se.fi
#define sse se.se
#define fse fi.se
#define lt(i, c, d) for(int i = c; i <= d; ++i)
#define fl(i, c, d) for(int i = d; i >= c; --i)
#define pb push_back
#define emb emplace_back
#define emf emplace_front
#define em emplace
#define look_memory cerr<<abs(&M2-&M1)/1024.0/1024<<'\n'
#define look_time   cerr << "TIME : " << clock() * 0.001 << "s" <<'\n'
const int N=5e5+5,lg=19,mod=1e9+7;
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int u,int v){
 return u+rd()%(v-u+1);
}
int dx[]={1,0,-1,0,1,1,-1,-1};
int dy[]={0,-1,0,1,1,-1,1,-1};
int node,k,tin[N],tout[N],timer,h[N],up[N][lg+5],g[N];
struct DSU
{
    int n;
    vector<int>r;
    DSU(){};
    DSU(int _n):n(_n),r(n+5,-1){};
    int acs(int u){
        return r[u]<0?u:r[u]=acs(r[u]);
    }
    void join(int u,int v){
        u=acs(u);
        v=acs(v);
        if(u!=v){
        if(h[u]>h[v])swap(u,v);
            r[u]+=r[v];
            r[v]=u;
        }
    }
};
ii b[N];
vector<int>mau[N];
vector<int>ver[N];
void addedge(int u,int v){
    ver[u].emb(v);
    ver[v].emb(u);
}

void dfs(int u,int cha)
{
    tin[u]=++timer;
    for(auto v:ver[u])
    {
        if(v==cha)continue;
        up[v][0]=u;
        h[v]=h[u]+1;
        dfs(v,u);
    }
    tout[u]=timer;
}

int lca(int u,int v)
{
    if(h[u]<h[v])swap(u,v);
    for(int j=lg;j>=0;--j)
       {
        if(h[u]-h[v]>=(1<<j))
            u=up[u][j];
       }
     if(u==v)return u;
     for(int j=lg;j>=0;--j)
     {
        if(up[u][j]!=up[v][j])
        {
            u=up[u][j];
            v=up[v][j];
        }
     }
    return up[u][0];
}

void build(){
    dfs(1,-1);
    for(int j=1;j<=lg;++j)
    for(int i=1;i<=node;++i)up[i][j]=up[up[i][j-1]][j-1];
}
namespace xuly{
    int dem[N];
    int slla=0;
    void solve(){

        for(int i=1;i<node;++i){
            auto[u,v]=b[i];
            u=g[u];
            v=g[v];
            if(u!=v){
                dem[u]++;
                dem[v]++;
            }
        }
        for(int i=1;i<=node;++i)if(dem[i]==1)++slla;
        cout <<(slla+1)/2;
    }
}

bool M2;
void solve(){
    cin >> node >> k;
    for(int i=1;i<node;++i){
        cin >> b[i].fi >> b[i].se;
        ver[b[i].fi].emb(b[i].se);
        ver[b[i].se].emb(b[i].fi);
    }
    build();
    DSU dsu(node);
    for(int i=1;i<=node;++i){
        int c;
        cin >> c;
        mau[c].emb(i);
    }
    for(int i=1;i<=k;++i){
        sort(all(mau[i]),[&](int u,int v){
            return tin[u]<tin[v];
        });
        for(int j=0;j<sz(mau[i]);++j){
            int u=mau[i][j],v=mau[i][(j+1)%sz(mau[i])];
            u=dsu.acs(u);
            v=dsu.acs(v);
            int l=lca(u,v);
            while(h[u]>h[l]){
                dsu.join(u,up[u][0]);
                u=dsu.acs(up[u][0]);
            }
            while(h[v]>h[l]){
                dsu.join(v,up[v][0]);
                v=dsu.acs(up[v][0]);
            }
        }
    }
    for(int i=1;i<=node;++i)g[i]=dsu.acs(i);
    xuly::solve();
    // for(int i=1;i<=node;++i)cout <<dsu.acs(i)<<" ";
}
main()
{
  srand(time(0));
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    #define task "aws"
    if(fopen(task".inp","r")){
      freopen(task".inp","r",stdin);
      freopen(task".out","w",stdout);
    }
    int t=1;
 //   cin >> t;
while(t--){
    solve();cout<<'\n';
}
look_memory;
look_time;
}

컴파일 시 표준 에러 (stderr) 메시지

mergers.cpp:154:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  154 | main()
      | ^~~~
mergers.cpp: In function 'int main()':
mergers.cpp:162:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  162 |       freopen(task".inp","r",stdin);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
mergers.cpp:163:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  163 |       freopen(task".out","w",stdout);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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