Submission #211045

#	Time	Username	Problem	Language	Result	Execution time	Memory
211045		HNO2	Designated Cities (JOI19_designated_cities)	C++17	100 / 100	1128 ms	80548 KiB

designated_cities

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const int maxn=2e5+7;
const int inf=INT_MAX;
const ll inff=1e18;
const ll mod=1e9+7;
#define pii pair<int,int>
#define mkp make_pair
#define F first
#define S second
#define pb push_back
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(),(v).end()
#define int ll

#ifdef HNO2
#define IOS
#else
#define endl '\n'
#define IOS ios::sync_with_stdio(0); cin.tie(0);
#endif // HNO2

int x[maxn*2],y[maxn*2],w[maxn*2];
int indeg[maxn];
vector <int> G[maxn];

int ans[maxn];
int tmpsum=0;

pii maxx[maxn];

int root,root2;

void dfs(int now,int p)
{
    for (int i:G[now])
        if ((x[i]^y[i]^now)!=p)
    {
        ans[1]+=w[i];
        dfs((x[i]^y[i]^now),now);
    }
}

void dfs2(int now,int p)
{
    ans[1]=min(ans[1],tmpsum);
    for (int i:G[now])
        if ((x[i]^y[i]^now)!=p)
    {
        tmpsum-=(w[i]-w[i^1]);
        dfs2((x[i]^y[i]^now),now);
        tmpsum+=(w[i]-w[i^1]);
    }
}

void dfs3(int now,int p)
{
    pair<pii,pii> nowmax=mkp(mkp(-inff,-inff),mkp(-inff,-inff));

    if (sz(G[now])==1)
    {
        maxx[now]=mkp(0,now);
        return;
    }

    for (int i:G[now])
        if ((x[i]^y[i]^now)!=p)
    {
        int I=(x[i]^y[i]^now);
        tmpsum-=(w[i]-w[i^1]);
        dfs3(I,now);

        //renew
        pii nowpair=mkp(maxx[I].F+w[i],maxx[I].S);
        if (nowpair>=nowmax.F) nowmax.S=nowmax.F,nowmax.F=nowpair;
        else if (nowpair>=nowmax.S) nowmax.S=nowpair;
        //

        tmpsum+=(w[i]-w[i^1]);
    }

    if (nowmax.F.F!=-inff&&nowmax.S.F!=-inff&&ans[2]>tmpsum-nowmax.F.F-nowmax.S.F)
        ans[2]=tmpsum-nowmax.F.F-nowmax.S.F,root=nowmax.F.S,root2=nowmax.S.S;
    maxx[now]=nowmax.F;
}

void dfs4(int now,int p)
{
     for (int i:G[now])
        if ((x[i]^y[i]^now)!=p)
    {
        tmpsum+=w[i];
        dfs4((x[i]^y[i]^now),now);
    }
}

int pp[maxn],weight[maxn],used[maxn];
int L[maxn],R[maxn],rL[maxn];
int Cnt=1;

struct segtree
{
    pii seg[maxn*4];
    int tag[maxn*4];

    void Build(int now,int l,int r)
    {
        if (l==r)
        {
            seg[now]=mkp(0,l);
            return;
        }
        int m=(l+r)>>1;
        Build(now*2,l,m);
        Build(now*2+1,m+1,r);
        seg[now]=max(seg[now*2],seg[now*2+1]);
    }

    void push(int now,int l,int r)
    {
        if (tag[now]==0||l==r)
        {
            tag[now]=0;
            return;
        }
        seg[now*2].F+=tag[now];
        tag[now*2]+=tag[now];
        seg[now*2+1].F+=tag[now];
        tag[now*2+1]+=tag[now];
        tag[now]=0;
    }

    void modify(int now,int l,int r,int ql,int qr,int v)
    {
        //cout<<now<<' '<<l<<' '<<r<<' '<<ql<<' '<<qr<<endl;
        if (l>=ql&&r<=qr)
        {
            seg[now].F+=v;
            tag[now]+=v;
            return;
        }
        int m=(l+r)>>1;
        push(now,l,r);
        if (ql<=m) modify(now*2,l,m,ql,qr,v);
        if (qr>m) modify(now*2+1,m+1,r,ql,qr,v);
        seg[now]=max(seg[now*2],seg[now*2+1]);
    }

    pii query()
    {
        return seg[1];
    }
}seg;

void dfs5(int now,int p)
{
    pp[now]=p;
    L[now]=Cnt++;
    rL[L[now]]=now;
    for (int i:G[now])
        if ((x[i]^y[i]^now)!=p)
    {
        weight[(x[i]^y[i]^now)]=w[i];
        dfs5((x[i]^y[i]^now),now);
    }
    R[now]=Cnt-1;
}

void use(int xx,int n)
{
    while (!used[xx])
    {
        used[xx]=1;
        seg.modify(1,1,n,L[xx],R[xx],-weight[xx]);
        xx=pp[xx];
    }
}

int32_t main()
{
    IOS
    int n;
    cin>>n;
    for (int i=1;i<=n;i++) ans[i]=inff;

    int _=0;
    for (int i=1;i<=n-1;i++)
    {
        int X,Y,Z,W;
        cin>>X>>Y>>Z>>W;
        x[_]=X,y[_]=Y,w[_]=Z;
        x[_^1]=Y,y[_^1]=X,w[_^1]=W;
        G[X].pb(_);
        G[Y].pb(_^1);
        _+=2;
        indeg[X]++;
        indeg[Y]++;
    }
    //1: calculate ans[1]
    ans[1]=0;
    dfs(1,-1);
    tmpsum=ans[1];
    dfs2(1,-1);
    //
    //2: ans[2]
    if (n==2)
    {
        ans[2]=0;
        int q;
        cin>>q;
        while (q--)
        {
            int X;
            cin>>X;
            cout<<ans[X]<<endl;
        }
        return 0;
    }
    for (int i=1;i<=n;i++)
        if (indeg[i]>=2)
        {
            tmpsum=0;
            dfs4(i,-1);
            dfs3(i,-1);
            break;
        }
    //
    //3: using ans[2] to calculate ans[i]
    seg.Build(1,1,n);
    dfs5(root,-1);
    for (int i=1;i<=n;i++)
        if (i!=root) seg.modify(1,1,n,L[i],R[i],weight[i]);
    used[root]=1;
    use(root2,n);

    //cout<<"Hi"<<endl;
    seg.modify(1,1,n,L[root],L[root],-inff);
    //cout<<seg.query().F<<endl;
    seg.modify(1,1,n,L[root2],L[root2],-inff);
   //cout<<seg.query().F<<endl;
    for (int i=3;i<=n;i++)
    {
        ans[i]=ans[i-1];
        pii ret=seg.query();
        ans[i]-=ret.F;
        use(rL[ret.S],n);
        seg.modify(1,1,n,ret.S,ret.S,-inff);
    }
    //
    int q;
    cin>>q;
    while (q--)
    {
        int X;
        cin>>X;
        cout<<ans[X]<<endl;
    }
    //
}

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 9 / 9
• Subtask 4: 17 / 17
• Subtask 5: 17 / 17
• Subtask 6: 44 / 44