제출 #866426

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
866426		yeediot	Cat Exercise (JOI23_ho_t4)	C++14	100 / 100	325 ms	70852 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
//Don't open the standings during contests.
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
const int mxn=2e5+5;
vector<int>adj[mxn];
int h[mxn],root,cnt[mxn],dep[mxn],to[mxn],dp[mxn];
int jump[20][mxn];
vector<pii>ord;
int cur=0;
void cntsz(int v,int pa){
    cnt[v]=1;
    dep[v]=dep[pa]+1;
    jump[0][v]=pa;
    for(auto u:adj[v]){
        if(u==pa)continue;
        cntsz(u,v);
        cnt[v]+=cnt[u];
    }
}
void build(int n){
    for(int i=1;i<20;i++){
        for(int j=1;j<=n;j++){
            jump[i][j]=jump[i-1][jump[i-1][j]];
        }
    }
}
int lca(int v,int u){
    if(dep[v]<dep[u])swap(v,u);
    int dif=dep[v]-dep[u];
    for(int i=0;i<20;i++){
        if(dif>>i&1){
            v=jump[i][v];
        }
    }
    if(u==v)return v;
    for(int i=19;i>=0;i--){
        if(jump[i][u]!=jump[i][v]){
            v=jump[i][v];
            u=jump[i][u];
        }
    }
    return jump[0][v];
}
int find(int x){
    return x==to[x]?x:to[x]=find(to[x]);
}
int dist(int a,int b){
    return dep[a]+dep[b]-2*dep[lca(a,b)];
}
void merge(int a,int b){
    a=find(a),b=find(b);
    chmax(dp[b],dp[a]+dist(a,b));
    to[a]=b;
}
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n;
    cin>>n;
    for(int i=1;i<=n;i++){
        to[i]=i;
        cin>>h[i];
        ord.pb({h[i],i});
        if(h[i]==n)root=i;
    }
    sort(all(ord));
    for(int i=1;i<n;i++){
        int a,b;
        cin>>a>>b;
        adj[a].pb(b);
        adj[b].pb(a);
    }
    cntsz(root,root);
    build(n);
    int ans=0;
    for(auto [he,x]:ord){
        for(auto u:adj[x]){
            if(h[u]<he){
                merge(u,x);
            }
        }
        chmax(ans,dp[x]);
    }
    cout<<ans<<'\n';
}
 /*
 input:
  1 0
  1 1
  1 0
  
  0 1
  0 1
  0 1
 
  0 0
  0 0
  0 0
  
  1 1
  1 0
  1 1
  
  
  1 1 1
  1 0 1
  1 1 0
  1 0 0
  1 1 1
  
  1 1 0
  
  0 1 1
  0 1 0
  0 1 1
  
  
 */

컴파일 시 표준 에러 (stderr) 메시지

Main.cpp: In function 'int main()':
Main.cpp:92:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   92 |     for(auto [he,x]:ord){
      |              ^
Main.cpp: In function 'void setIO(std::string)':
Main.cpp:17:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:18:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 23 / 23
• Subtask 7: 26 / 26