NOIP模拟22

T1d

一道垃圾贪心，写个堆优化或者桶就行

#include<bits/stdc++.h>
#define int long long
using namespace std;
inline int read()
{
    int x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
        if(ch=='-') f=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
    {
        x=(x<<1)+(x<<3)+(ch^48);
        ch=getchar();
    }
    return x*f;
}
int n,m;
const int maxn=2e5;
struct matrix{
    int a,b,id;
}jx[maxn],aa[maxn],bb[maxn];
bool cmp1(matrix a,matrix b)
{
    if(a.b!=b.b)
    return a.b<b.b;
    return b.a<b.a;
}
bool cmp2(matrix a,matrix b)
{
    if(a.a!=b.a)
    return a.a<b.a;
    return b.b<b.b;
}
int tonga[maxn],tongb[maxn];
bool vis[maxn];
signed main()
{
    int t=read();
    while(t--)
    {
        memset(tonga,0,sizeof(tonga));
        memset(tongb,0,sizeof(tongb));
        memset(vis,0,sizeof(vis));
        n=read(),m=read();
        for(int i=1;i<=n;i++) 
        {
            aa[i].a=bb[i].a=jx[i].a=read();
            tonga[jx[i].a]++;
            aa[i].b=bb[i].b=jx[i].b=read();
            tongb[jx[i].b]++;
            aa[i].id=i,bb[i].id=i;
        }
        sort(aa+1,aa+1+n,cmp2);
        sort(bb+1,bb+1+n,cmp1);
        for(int i=1;i<=m;i++)
        tonga[aa[i].a]--,tongb[aa[i].b]--,vis[aa[i].id]=1;
        int tempa=0,tempb=0,tmp=1,ans=0;
        while(!tonga[tempa]) tempa++;
        while(!tongb[tempb]) tempb++;
        ans=max(ans,tempb*tempa);
        for(int i=1;i<=m;i++)
        {
            if(aa[m-i+1].b<=tempb) continue;
            vis[aa[m-i+1].id]=0;
            ++tonga[aa[m-i+1].a];
            ++tongb[aa[m-i+1].b];
            if(aa[m-i+1].a<tempa) tempa=aa[m-i+1].a;
            while(vis[bb[tmp].id]) tmp++;
            vis[bb[tmp].id]=1,tongb[bb[tmp].b]--,tonga[bb[tmp].a]--;
            while(!tonga[tempa]) tempa++;
            while(!tongb[tempb]) tempb++;
            ans=max(ans,tempb*tempa);
        }
        cout<<ans<<endl;
    }
}

T2e

正解是主席树？？？？？

主席树没有学怎么办？？？？

如果想写这个题，首先你要学习线段树套平衡树技巧（二逼平衡树），以及树链剖分在线段树上的应用;

结合起来！！！！！！！！！！！

写个树链剖分+线段树+平衡树可以过非一条链的点，

一条链上的暴力跳lca就好了，只不过码起来真tm爽！！！！！！！！

#include<bits/stdc++.h>
#define inf 2e9
#define lid id<<1
#define rid id<<1|1
using namespace std;
inline int read()
{
    int x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
        if(ch=='-') f=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
    {
        x=(x<<1)+(x<<3)+(ch^48);
        ch=getchar();
    }
    return x*f;
}
const int maxn=2e6+1;
struct treap{
    int l,r,size,cnt,dat,val;
}a[maxn];
struct seg_tree{
    int l,r,root,lazy;
}tr[maxn<<2];
int n,q,type,tot;
struct node{
    int to,nxt;
}e[maxn*2];
int head[maxn];
bool flag=1;
int val[maxn];
bool vis[100001];
int w[maxn],num;
int dfn[maxn],size[maxn],son[maxn],fa[maxn],top[maxn];
int dep[maxn],cnt;
int cz[maxn],rr,k;
inline void add(int x,int y)
{
    e[++num].to=y;
    e[num].nxt=head[x];
    head[x]=num;
    if(x!=y+1&&y!=x+1) flag=0;
    swap(x,y);
    e[++num].to=y;
    e[num].nxt=head[x];
    head[x]=num;
}
inline int New(int val)
{
    a[++tot].val=val;
    a[tot].dat=rand();
    a[tot].cnt=a[tot].size=1;
    return tot;
}
inline void pushup(int p)
{
    a[p].size=a[a[p].l].size+a[a[p].r].size+1;
}
inline int merge(int x,int y)
{
    if(!x||!y)
    return x|y;
    if(a[x].dat<a[y].dat)
    {
        a[x].r=merge(a[x].r,y);
        pushup(x);
        return x;
    }
    else
    {
        a[y].l=merge(x,a[y].l);
        pushup(y);
        return y;
    }
}
inline void split(int now,int kk,int &x,int &y)
{
    if(!now)
    {
        x=y=0;
        return ;
    }
    if(kk>=a[now].val)
    {
        x=now;
        split(a[now].r,kk,a[now].r,y);
    }
    else
    {
        y=now;
        split(a[now].l,kk,x,a[now].l);
    }
    pushup(now);
}
inline void insert(int &root,int val)
{
    int x,y;
    split(root,val,x,y);
    root=merge(merge(x,New(val)),y);    
}
void build(int id,int l,int r)
{
    tr[id].l=l; tr[id].r=r;
    if(l==r)
    {
        tr[id].root=New(w[l]);
        return ;
    }
    for(int j=l;j<=r;j++)
    insert(tr[id].root,w[j]);
    int mid=(l+r)>>1;
    build(lid,l,mid);
    build(rid,mid+1,r);
}
inline int pre(int &root,int val)
{
    int x,y,ans;
    split(root,val-1,x,y);
    if(!x) return -inf;
    int kk=x;
    while(a[kk].r)
    kk=a[kk].r;
    ans=a[kk].val;
    root=merge(x,y);
    return ans;
}
inline int nxt(int &root,int val)
{
    int x,y,ans;
    split(root,val,x,y);
    if(!y) return inf;
    int kk=y;
    while(a[kk].l)
    kk=a[kk].l;
    ans=a[kk].val;
    root=merge(x,y);
    return ans;
}
inline int askpre(int id,int l,int r,int d)
{
    if(tr[id].l>=l&&tr[id].r<=r)
    return pre(tr[id].root,d);
    int mid=(tr[id].l+tr[id].r)>>1;
    int ans=-inf;
    if(l<=mid)
    ans=max(ans,askpre(lid,l,r,d));
    if(r>mid)
    ans=max(ans,askpre(rid,l,r,d));
    return ans;
}
inline int asknxt(int id,int l,int r,int d)
{
    if(tr[id].l>=l&&tr[id].r<=r)
    return nxt(tr[id].root,d);
    int mid=(tr[id].l+tr[id].r)>>1;
    int ans=inf;
    if(l<=mid)
    ans=min(ans,asknxt(lid,l,r,d));
    if(r>mid)
    ans=min(ans,asknxt(rid,l,r,d));
    return ans;
}
void dfs1(int x,int f)
{
    size[x]=1;
    for(int i=head[x];i;i=e[i].nxt)
    {
        int y=e[i].to;
        if(y==f) continue;
        dep[y]=dep[x]+1;
        fa[y]=x;
        dfs1(y,x);
        size[x]+=size[y];
        if(size[son[x]]<size[y]) 
        son[x]=y;
    }
}
void dfs2(int x,int f)
{
    top[x]=f;
    dfn[x]=++cnt;
    w[cnt]=val[x];
    if(!son[x]) return ;
    dfs2(son[x],f);
    for(int i=head[x];i;i=e[i].nxt)
    {
        int y=e[i].to;
        if(y!=fa[x]&&y!=son[x])
        dfs2(y,y);
    }
}
inline int treepre(int x,int y,int jb)
{
    int ans=-inf;
    while(top[x]!=top[y])
    {
        if(dep[top[x]]<dep[top[y]])
        swap(x,y);
        ans=max(ans,askpre(1,dfn[top[x]],dfn[x],jb));
        x=fa[top[x]];
    }
    if(dep[x]>dep[y])
    swap(x,y);
    ans=max(ans,askpre(1,dfn[x],dfn[y],jb));
    return ans;
}
inline int treenxt(int x,int y,int jb)
{
    int ans=inf;
    while(top[x]!=top[y])
    {
        if(dep[top[x]]<dep[top[y]])
        swap(x,y);
        ans=min(ans,asknxt(1,dfn[top[x]],dfn[x],jb));
        x=fa[top[x]];
    }
    if(dep[x]>dep[y])
    swap(x,y);
    ans=min(ans,asknxt(1,dfn[x],dfn[y],jb));
    return ans;
}
inline int LCA(int x, int y) 
{
        while(top[x]!=top[y]) 
        {
             if(dep[top[x]]<dep[top[y]]) 
            swap(x,y);
            x=fa[top[x]];
        }
        return dep[x]<dep[y]?x:y;
}
inline void dfs3(int x,int goal,int &sum)
{
    if(!x) return ;
    if(vis[x])  return ;
    vis[x]=1;
    sum=min(sum,abs(val[x]-rr));
    if(x==goal) return ;
    dfs3(fa[x],goal,sum);
}
signed main()
{
    //freopen("e7.in","r",stdin);
    //freopen("out","w",stdout);
    srand(time(0));
    n=read(),q=read(),type=read();
    for(int i=1;i<=n;i++) val[i]=read();
    for(int i=1;i<n;i++) add(read(),read());
    dfs1(1,0);
    dfs2(1,1);
    if(flag==1)
    {
        for(int i=1;i<=q;i++)
        {
            memset(vis,0,sizeof(vis));
            rr=read(),k=read();
            for(int j=1;j<=k;j++) cz[j]=read();
            int ans=inf;
            int lca=cz[1];
            for(int j=2;j<=k;j++) 
            lca=LCA(lca,cz[j]);
            for(int j=1;j<=k;j++)
            dfs3(cz[j],lca,ans);
            printf("%d\n",ans);
        }
        return 0;
    }
    else
    {
        build(1,1,n);
        int ans=0;
        for(int i=1;i<=q;i++)
        {
            rr=read(),k=read();
            for(int j=1;j<=k;j++) cz[j]=((read()-1+type*ans)%n)+1;
            ans=inf;
            int lca=cz[1];
            for(int j=2;j<=k;j++) 
            lca=LCA(lca,cz[j]);
            for(int j=1,tmp;j<=k;j++)
            {
                tmp=treepre(lca,cz[j],rr+1);
                if(ans>abs(tmp-rr)) ans=abs(tmp-rr);
                tmp=treenxt(lca,cz[j],rr-1);
                if(ans>abs(tmp-rr)) ans=abs(tmp-rr);
            }
            printf("%d\n",ans);
        }
    }
}

T3f

不会，先咕了