結果

問題 No.2677 Minmax Independent Set
ユーザー woodywoodywoodywoody
提出日時 2024-03-15 23:07:47
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 335 ms / 2,000 ms
コード長 7,184 bytes
コンパイル時間 4,257 ms
コンパイル使用メモリ 235,864 KB
実行使用メモリ 72,832 KB
最終ジャッジ日時 2024-09-30 02:42:32
合計ジャッジ時間 14,423 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 61
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include<bits/stdc++.h>
#include<atcoder/all>
#define rep(i,b) for(int i=0;i<b;i++)
#define rrep(i,b) for(int i=b-1;i>=0;i--)
#define rep1(i,b) for(int i=1;i<b;i++)
#define repx(i,x,b) for(int i=x;i<b;i++)
#define rrepx(i,x,b) for(int i=b-1;i>=x;i--)
#define fore(i,a) for(auto& i:a)
#define rng(x) (x).begin(), (x).end()
#define rrng(x) (x).rbegin(), (x).rend()
#define sz(x) ((int)(x).size())
#define pb push_back
#define fi first
#define se second
#define pcnt __builtin_popcountll

using namespace std;
using namespace atcoder;

using ll = long long;
using ld = long double;
template<typename T> using mpq = priority_queue<T, vector<T>, greater<T>>;
template<typename T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<typename T> bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
template<typename T> ll sumv(const vector<T>&a){ll res(0);for(auto&&x:a)res+=x;return res;}
bool yn(bool a) { if(a) {cout << "Yes" << endl; return true;} else {cout << "No" << endl; return false;}}
#define retval(x) {cout << #x << endl; return;}
#define cout2(x,y) cout << x << " " << y << endl;
#define coutp(p) cout << p.fi << " " << p.se << endl;
#define out cout << ans << endl;
#define outd cout << fixed << setprecision(20) << ans << endl;
#define outm cout << ans.val() << endl;
#define outv fore(yans , ans) cout << yans << "\n";
#define outdv fore(yans , ans) cout << yans.val() << "\n";
#define assertmle(x) if (!(x)) {vi v(3e8);}
#define asserttle(x) if (!(x)) {while(1){}}
#define coutv(v) {fore(vy , v) {cout << vy << " ";} cout << endl;}
#define coutv2(v) fore(vy , v) cout << vy << "\n";
#define coutvm(v) {fore(vy , v) {cout << vy.val() << " ";} cout << endl;}
#define coutvm2(v) fore(vy , v) cout << vy.val() << "\n";
using pll = pair<ll,ll>;using pil = pair<int,ll>;using pli = pair<ll,int>;using pii = pair<int,int>;using pdd = pair<ld,ld>;
using vi = vector<int>;using vd = vector<ld>;using vl = vector<ll>;using vs = vector<string>;using vb = vector<bool>;
using vpii = vector<pii>;using vpli = vector<pli>;using vpll = vector<pll>;using vpil = vector<pil>;
using vvi = vector<vector<int>>;using vvl = vector<vector<ll>>;using vvs = vector<vector<string>>;using vvb = vector<vector<bool>>;
using vvpii = vector<vector<pii>>;using vvpli = vector<vector<pli>>;using vvpll = vector<vpll>;using vvpil = vector<vpil>;
using mint = modint998244353;
//using mint = modint1000000007;
//using mint = dynamic_modint<0>;
using vm = vector<mint>;
using vvm = vector<vector<mint>>;
vector<int> dx={1,0,-1,0,1,1,-1,-1},dy={0,1,0,-1,1,-1,1,-1};
ll gcd(ll a, ll b) { return a?gcd(b%a,a):b;}
ll lcm(ll a, ll b) { return a/gcd(a,b)*b;}
#define yes {cout <<"Yes"<<endl;}
#define no {cout <<"No"<<endl;}
const double eps = 1e-10;
const ll LINF = 2001002003004005006ll;
const int INF = 1001001001;
#ifdef MY_LOCAL_DEBUG
#include "./debug/localDebug.cpp"
#define showp(p) cerr<<#p<<" = "<<p.fi<<" : "<<p.se<<endl
#define show1(a) cerr<<#a<<" = "<<a<<endl
#define show2(a,b) cerr<<#a<<" = "<<a<<" : "<<#b<<" = "<<b<<endl
#define show3(a,b,c) cerr<<#a<<" = "<<a<<" : "<<#b<<" = "<<b<<" : "<<#c<<" = "<<c<<endl
#define show4(a,b,c,d) cerr<<#a<<" = "<<a<<" : "<<#b<<" = "<<b<<" : "<<#c<<" = "<<c<<" : "<<#d<<" = "<<d<<endl
#define show5(a,b,c,d,e) cerr<<#a<<" = "<<a<<" : "<<#b<<" = "<<b<<" : "<<#c<<" = "<<c<<" : "<<#d<<" = "<<d<<" : "<<#e<<" = "<<e<<endl
#define DEBUG_LINE cout << "DEBUG_LINE : " << __LINE__ << endl
#define showv(v) {cout<<#v<<" : "; fore(vy , v) {cout << vy << " ";} cout << endl;}
#define showv2(v) {cout<<#v<<endl; fore(vy , v) cout << vy << "\n";}
#define showvm(v) {cout<<#v<<" : "; fore(vy , v) {cout << vy.val() << " ";} cout << endl;}
#define showvm2(v) {cout<<#v<<endl; fore(vy , v) cout << vy.val() << "\n";}
#define showmat(v) {cout<<#v<<endl; fore(row , v) { fore(seg , row) cout << seg << " "; cout << endl;}}
#define showmatm(v) {cout<<#v<<endl; fore(row , v) { fore(seg , row) cout << seg.val() << " "; cout << endl;}}
#else
#define showp(p)
#define show1(a)
#define show2(a,b)
#define show3(a,b,c)
#define show4(a,b,c,d)
#define show5(a,b,c,d,e)
#define DEBUG_LINE
#define showv(v)
#define showv2(v)
#define showvm(v)
#define showvm2(v)
#define showmat(v)
#define showmatm(v)
#endif
#define overload5(a,b,c,d,e,f, ...) f
#define show(...) overload5(__VA_ARGS__, show5, show4, show3, show2, show1)(__VA_ARGS__)

pii op(pii a, pii b){
    return {a.fi + max(b.fi, b.se), a.se + b.fi};
}

struct ReRooting {

    using F1 = function<pii(pii, pii)>;
    using F2 = function<pii()>;

    int n; // 頂点数
    vvi e,tmp_edge; // e:edge情報 親は最後に入る
    vector<vector<pii>> dp; // dp[x][i]、iはeに連動
    vector<vector<pii>> lsum; // 左(右)からの累積和 
    vector<int> ans;
    pii id = {0,1};

    ReRooting(int n) : n(n),e(n),tmp_edge(n),dp(n),lsum(n),ans(n,INF){}

    void add_edge(int u, int v) {
        tmp_edge[u].pb(v);
        tmp_edge[v].pb(u);
    }

    pii dfs1(int x, int pre) {
        pii ret = id;
        int i = 0;
    
        fore(y , tmp_edge[x]){
            if (y == pre) continue;
        
            dp[x].pb(dfs1(y , x));
            e[x].pb(y);
            ret = op(ret , dp[x][i]);
        
            lsum[x].pb(id);
        
            i++;
        }
    
        if (pre != -1){
            e[x].pb(pre);
            dp[x].pb(id);
            lsum[x].pb(id);
        }
    
        return ret;
    }

    void dfs2(int x,int pre,pii preval) {
        int m = sz(e[x]);
    
        if (pre != -1) dp[x][m-1] = preval;
    
        rep(i,m){
            if (i==0){
                lsum[x][i] = id;
            }else{
                lsum[x][i] = lsum[x][i-1];
            }
            lsum[x][i] = op(lsum[x][i], dp[x][i]);
        }
    
        if (m >= 1) ans[x] = lsum[x][m-1].se;

        pii now = {0,0};
    
        rrep(i,m){
            int y = e[x][i];
            if (y == pre){
                now.fi = dp[x][i].fi;
                now.se = max(dp[x][i].fi, dp[x][i].se);
                continue;
            }

            pii nxtval = id;
            if (i != 0) nxtval = lsum[x][i-1];
            if (i != m-1){
                nxtval.fi += now.se;
                nxtval.se += now.fi;
            }
        
            dfs2(y , x , nxtval);

            now.fi += dp[x][i].fi;
            now.se += max(dp[x][i].fi, dp[x][i].se);
        }
    
        return;
    }

    void solve(){
        dfs1(0,-1);
        dfs2(0,-1,id);
    }
};

// 全方位木dp
// ReRooting<pii> rr(n,op,id) : 初期化。nは頂点数、opはmerge演算関数、idは単位元
// op,idはラムダ式で定義
// add_edge(a,b) a,b間に辺を引く
// solve() dp実行、ansに答えが入る。

// dfs内は適宜変更すること


void solve(){
    int n; cin>>n;

    ReRooting rr(n);
    rep(i,n-1){
        int a,b; cin>>a>>b;
        a--; b--;
        rr.add_edge(a,b);
    }

    if (n==1) retval(1);

    rr.solve();
    int ans = INF;
    rep(i,n) chmin(ans, rr.ans[i]);
    out;

    return;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);

    int t = 1;
    //cin>>t;

    rep(i,t){
        solve();
    }

    return 0;
}
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