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    1.FFT

     1 void fft(int n,Complex *x,int cvs)
     2 {
     3     for (int i=0,j=0;i<n;i++)
     4     {
     5         if (i<j) swap(x[i],x[j]);
     6         for (int l=(n>>1);(j^=l)<l;l>>=1);
     7     }
     8     for (int i=2;i<=n;i<<=1)
     9     {
    10         int l=(i>>1);
    11         for (int j=0;j!=n;j+=i)
    12         {
    13             Complex wn,w;
    14             wn=Complex(1,0);
    15             w=Complex(cos(2*pi/i*cvs),sin(2*pi/i*cvs));
    16             for (int k=0;k<l;k++)
    17             {
    18                 Complex t=wn*x[j+l+k];
    19                 x[j+l+k]=x[j+k]-t;
    20                 x[j+k]=x[j+k]+t;
    21                 wn=wn*w;
    22             }
    23         }
    24     }
    25 }
    FFT

    2.Splay

      1 #include <bits/stdc++.h>
      2 #define inf (int)1e9
      3 using namespace std;
      4 const int N=1e5+100;
      5 int n,tot,root,val[N],sz[N],son[N][2];
      6 int fa[N],sf[N],re[N];
      7 int newnode()
      8 {
      9     return tot++;
     10 }
     11 void connect(int x,int y,int dir)
     12 {
     13     son[y][dir]=x;
     14     fa[x]=y;
     15     sf[x]=dir;
     16 }
     17 void pushup(int x)
     18 {
     19     sz[x]=sz[son[x][0]]+sz[son[x][1]]+re[x];
     20 }
     21 void clear()
     22 {
     23     val[0]=son[0][0]=son[0][1]=sz[0]=re[0]=fa[0]=sf[0]=0;
     24 }
     25 void rotate(int x)
     26 {
     27     int f,gf,xd,fd,s;
     28     f=fa[x];gf=fa[f];
     29     xd=sf[x];fd=sf[f];
     30     s=son[x][xd^1];
     31     connect(x,gf,fd);connect(f,x,xd^1);connect(s,f,xd);
     32     clear();
     33     pushup(f);pushup(x);
     34 }
     35 void splay(int x,int y)
     36 {
     37     while (fa[x]!=y)
     38     {
     39         if (fa[fa[x]]==y)
     40           rotate(x);
     41         else
     42         if (sf[fa[x]]==sf[x])
     43         {
     44             rotate(fa[x]);
     45             rotate(x);
     46         }
     47         else
     48         {
     49             rotate(x);
     50             rotate(x);
     51         }
     52     }
     53     if (y==0)
     54       root=x;
     55 }
     56 void find(int v)
     57 {
     58     int cur=root;
     59     while (son[cur][v>val[cur]] && val[cur]!=v)
     60       cur=son[cur][v>val[cur]];
     61     splay(cur,0);
     62 }
     63 int per(int v)
     64 {
     65     find(v);
     66     if (val[root]<v) return root;
     67     int cur=son[root][0];
     68     while (son[cur][1]) cur=son[cur][1];
     69     return cur;
     70 }
     71 int suc(int v)
     72 {
     73     find(v);
     74     if (val[root]>v) return root;
     75     int cur=son[root][1];
     76     while (son[cur][0]) cur=son[cur][0];
     77     return cur;
     78 }
     79 void insert(int v)
     80 {
     81     
     82     if (root==0)
     83     {
     84         int x=newnode();
     85         val[x]=v;sz[x]=1;
     86         root=x;
     87         return;
     88     }
     89     int cur=root;
     90     while (son[cur][v>val[cur]] && val[cur]!=v)
     91       cur=son[cur][v>val[cur]];
     92     if (val[cur]==v)
     93     {
     94         re[cur]++;sz[cur]++;
     95         splay(cur,0);
     96         return;
     97     }
     98     int x=newnode();
     99     val[x]=v;re[x]=sz[x]=1;
    100     connect(x,cur,v>val[cur]);
    101     pushup(cur);
    102     splay(x,0);
    103 }
    104 void del(int v)
    105 {
    106     int p,s;
    107     p=per(v);s=suc(v);
    108     splay(p,0);
    109     splay(s,p);
    110     re[son[s][0]]--;sz[son[s][0]]--;
    111     if (re[son[s][0]]==0)
    112       son[s][0]=0;
    113     pushup(s);pushup(p);
    114 }
    115 int rk(int v)
    116 {
    117     find(v);
    118     return sz[son[root][0]];
    119 }
    120 int kth(int x,int k)
    121 {
    122     if (k>sz[son[x][0]]+re[x])
    123       return kth(son[x][1],k-sz[son[x][0]]-re[x]);
    124     if (k<=sz[son[x][0]])
    125       return kth(son[x][0],k);
    126     return x;
    127 }
    128 int main()
    129 {
    130     tot=1;
    131     insert(inf);insert(-inf);
    132     scanf("%d",&n);
    133     for (int i=1;i<=n;i++)
    134     {
    135         int op,x;
    136         scanf("%d%d",&op,&x);
    137         if (op==1) insert(x);
    138         if (op==2) del(x);
    139         if (op==3) printf("%d
    ",rk(x));
    140         if (op==4) printf("%d
    ",val[kth(root,x+1)]);
    141         if (op==5) printf("%d
    ",val[per(x)]);
    142         if (op==6) printf("%d
    ",val[suc(x)]);
    143     }
    144 }
    普通平衡树
      1 #include <bits/stdc++.h>
      2 #define inf (int)1e9
      3 using namespace std;
      4 const int N=500100;
      5 int n,m,tot,root,a[N];
      6 struct node
      7 {
      8     int sz,val,sum,res,lx,rx,tx,vc;
      9     int son[2],fa,sf;
     10 }sh[N+100];
     11 queue <int> q;
     12 int newnode()
     13 {
     14     int x;
     15     if (tot>=N)
     16     {
     17         x=q.front();
     18         q.pop();
     19     }
     20     else
     21       x=tot++;
     22     sh[x].sz=sh[x].val=sh[x].sum=sh[x].res=sh[x].lx=sh[x].rx=sh[x].tx=sh[x].vc=0;
     23     sh[x].son[0]=sh[x].son[1]=sh[x].sf=sh[x].fa=0;
     24     sh[x].vc=inf;
     25     return x;
     26 }
     27 void clear(int x)
     28 {
     29     q.push(x);
     30     if (sh[x].son[0]) clear(sh[x].son[0]);
     31     if (sh[x].son[1]) clear(sh[x].son[1]);
     32 }
     33 void connect(int x,int y,int dir)//x->y
     34 {
     35     sh[y].son[dir]=x;
     36     sh[x].fa=y;
     37     sh[x].sf=dir;
     38 }
     39 void pushdown(int x)
     40 {
     41     int ls,rs;
     42     ls=sh[x].son[0];rs=sh[x].son[1];
     43     if (sh[x].res==1)
     44     {
     45         if (ls)
     46         {
     47             sh[sh[ls].son[0]].sf^=1;sh[sh[ls].son[1]].sf^=1;
     48             swap(sh[ls].son[0],sh[ls].son[1]);
     49             swap(sh[sh[ls].son[0]].lx,sh[sh[ls].son[0]].rx);
     50             swap(sh[sh[ls].son[1]].lx,sh[sh[ls].son[1]].rx);
     51             sh[ls].res^=1;
     52         }
     53         if (rs)
     54         {
     55             sh[sh[rs].son[0]].sf^=1;sh[sh[rs].son[1]].sf^=1;
     56             swap(sh[rs].son[0],sh[rs].son[1]);
     57             swap(sh[sh[rs].son[0]].lx,sh[sh[rs].son[0]].rx);
     58             swap(sh[sh[rs].son[1]].lx,sh[sh[rs].son[1]].rx);
     59             sh[rs].res^=1;
     60         }
     61         sh[x].res=0;
     62     }
     63     if (sh[x].vc!=inf)
     64     {
     65         if (ls)
     66         {
     67             sh[ls].val=sh[ls].vc=sh[x].vc;
     68             sh[ls].sum=sh[ls].val*sh[ls].sz;
     69             sh[ls].tx=max(sh[ls].val,sh[ls].val*sh[ls].sz);
     70             sh[ls].lx=sh[ls].rx=max(0,sh[ls].val*sh[ls].sz);
     71         }
     72         if (rs)
     73         {
     74             sh[rs].val=sh[rs].vc=sh[x].vc;
     75             sh[rs].sum=sh[rs].val*sh[rs].sz;
     76             sh[rs].tx=max(sh[rs].val,sh[rs].val*sh[rs].sz);
     77             sh[rs].lx=sh[rs].rx=max(0,sh[rs].val*sh[rs].sz);
     78         }
     79         sh[x].vc=inf;
     80     }
     81 }
     82 void pushup(int x)
     83 {
     84     int ls,rs;
     85     ls=sh[x].son[0];rs=sh[x].son[1];
     86     sh[x].sz=sh[ls].sz+sh[rs].sz+1;
     87     sh[x].sum=sh[ls].sum+sh[rs].sum+sh[x].val;
     88     sh[x].lx=max(sh[ls].lx,sh[ls].sum+sh[rs].lx+sh[x].val);
     89     sh[x].rx=max(sh[rs].rx,sh[rs].sum+sh[ls].rx+sh[x].val);
     90     sh[x].tx=max(sh[ls].tx,max(sh[rs].tx,sh[ls].rx+sh[rs].lx+sh[x].val));
     91 }
     92 void rotate(int x)
     93 {
     94     int fa,gf,son,xd,fd;
     95     fa=sh[x].fa;gf=sh[sh[x].fa].fa;
     96     xd=sh[x].sf;fd=sh[fa].sf;
     97     son=sh[x].son[xd^1];
     98     connect(x,gf,fd);connect(fa,x,xd^1);connect(son,fa,xd);
     99     sh[0].fa=sh[0].son[0]=sh[0].son[1]=sh[0].sf=0;
    100     pushup(fa);pushup(x);
    101 }
    102 void splay(int x,int y)
    103 {
    104     while (sh[x].fa!=y)
    105     {
    106         if (sh[sh[x].fa].fa==y)
    107           rotate(x);
    108         else
    109         if (sh[x].sf==sh[sh[x].fa].sf)
    110         {
    111             rotate(sh[x].fa);
    112             rotate(x);
    113         }
    114         else
    115         {
    116             rotate(x);
    117             rotate(x);
    118         }
    119     }
    120     if (y==0)
    121       root=x;
    122 }
    123 int find(int x,int k)
    124 {
    125     pushdown(x);
    126     if (k>sh[sh[x].son[0]].sz+1)
    127       return find(sh[x].son[1],k-sh[sh[x].son[0]].sz-1);
    128     if (k<=sh[sh[x].son[0]].sz)
    129       return find(sh[x].son[0],k);
    130     return x;
    131 }
    132 int build(int l,int r,int father,int dir)
    133 {
    134     int mid=(l+r)>>1;
    135     int x=newnode();
    136     sh[x].val=a[mid];
    137     sh[x].fa=father;sh[x].sf=dir;
    138     if (l==r)
    139     {
    140         sh[x].sz=1;
    141         sh[x].sum=sh[x].tx=a[mid];
    142         sh[x].lx=sh[x].rx=max(0,a[mid]);
    143         return x;
    144     }
    145     if (l<=mid-1)
    146       sh[x].son[0]=build(l,mid-1,x,0);
    147     if (r>=mid+1)
    148       sh[x].son[1]=build(mid+1,r,x,1);
    149     pushup(x);
    150     return x;
    151 }
    152 int split(int l,int r)
    153 {
    154     int per,suc;
    155     per=find(root,l);suc=find(root,r+2);
    156     splay(per,0);
    157     splay(suc,per);
    158     return sh[suc].son[0];
    159 }
    160 int main()
    161 {
    162     scanf("%d%d",&n,&m);
    163     for (int i=1;i<=n;i++)
    164       scanf("%d",&a[i]);
    165     tot=1;sh[0].tx=a[0]=a[n+1]=-inf;
    166     root=build(0,n+1,0,0);
    167     while (m--)
    168     {
    169         char ch[20];
    170         scanf("%s",ch);
    171         if (ch[0]=='I')
    172         {
    173             int pos,tot;
    174             scanf("%d%d",&pos,&tot);
    175             for (int i=1;i<=tot;i++)
    176               scanf("%d",&a[i]);
    177             int x=build(1,tot,0,0);
    178             int A,B;
    179             A=find(root,pos+1);B=find(root,pos+2);
    180             splay(A,0);splay(B,A);
    181             connect(x,B,0);
    182             pushup(B);pushup(A);
    183         }
    184         if (ch[0]=='D')
    185         {
    186             int pos,tot;
    187             scanf("%d%d",&pos,&tot);
    188             int per,suc;
    189             per=find(root,pos);suc=find(root,pos+tot+1);
    190             splay(per,0);
    191             splay(suc,per);
    192             clear(sh[suc].son[0]);
    193             sh[suc].son[0]=0;
    194             pushup(suc);pushup(per);
    195         }
    196         if (ch[0]=='M' && ch[2]=='K')
    197         {
    198             int pos,tot,c;
    199             scanf("%d%d%d",&pos,&tot,&c);
    200             int x=split(pos,pos+tot-1);
    201             sh[x].val=sh[x].vc=c;
    202             sh[x].sum=c*sh[x].sz;
    203             sh[x].tx=max(sh[x].val,c*sh[x].sz);
    204             sh[x].lx=sh[x].rx=max(0,c*sh[x].sz);
    205             pushup(sh[x].fa);pushup(sh[sh[x].fa].fa);
    206         }
    207         if (ch[0]=='R')
    208         {
    209             int pos,tot;
    210             scanf("%d%d",&pos,&tot);
    211             int x=split(pos,pos+tot-1);
    212             sh[x].res^=1;
    213             int ls,rs;
    214             ls=sh[x].son[0];rs=sh[x].son[1];
    215             sh[ls].sf^=1;sh[rs].sf^=1;
    216             swap(sh[x].son[0],sh[x].son[1]);
    217             swap(sh[ls].lx,sh[ls].rx);
    218             swap(sh[rs].lx,sh[rs].rx);
    219             pushup(x);pushup(sh[x].fa);pushup(sh[sh[x].fa].fa);
    220         }
    221         if (ch[0]=='G')
    222         {
    223             int pos,tot;
    224             scanf("%d%d",&pos,&tot);
    225             int x=split(pos,pos+tot-1);
    226             printf("%d
    ",sh[x].sum);
    227         }
    228         if (ch[0]=='M' && ch[2]=='X')
    229         {
    230             printf("%d
    ",sh[root].tx);
    231         }
    232     }
    233 }
    维护数列

    3.可持久化线段树

     1 #include <bits/stdc++.h>
     2 using namespace std;
     3 const int N=2*1e5+100;
     4 int n,m,a[N],b[N],tr[N];
     5 int root[N],cnt;
     6 struct node
     7 {
     8     int ls,rs,sz;
     9 }sh[N*40];
    10 int ask(int a)
    11 {
    12     int pos;
    13     pos=lower_bound(b+1,b+1+n,a)-b;
    14     return pos;
    15 }
    16 void pushup(int x)
    17 {
    18     int ls,rs;
    19     ls=sh[x].ls;rs=sh[x].rs;
    20     sh[x].sz=sh[ls].sz+sh[rs].sz;
    21 }
    22 int build(int &x,int l,int r)
    23 {
    24     if (!x) x=++cnt;
    25     if (l==r) return x;
    26     int mid=(l+r)>>1;
    27     sh[x].ls=build(sh[x].ls,l,mid);
    28     sh[x].rs=build(sh[x].rs,mid+1,r);
    29     pushup(x);
    30     return x;
    31 }
    32 int change(int x,int l,int r,int wh)
    33 {
    34     int p=++cnt;
    35     sh[p]=sh[x];
    36     if (l==r)
    37     {
    38         sh[p].sz++;
    39         return p;
    40     }
    41     int mid=(l+r)>>1;
    42     if (wh<=mid) sh[p].ls=change(sh[x].ls,l,mid,wh);
    43     else sh[p].rs=change(sh[x].rs,mid+1,r,wh);
    44     pushup(p);
    45     return p;
    46 }
    47 int query(int lx,int rx,int l,int r,int k)
    48 {
    49     if (l==r) return l;
    50     int lz,mid;
    51     mid=(l+r)>>1;
    52     lz=sh[sh[rx].ls].sz-sh[sh[lx].ls].sz;
    53     if (k<=lz) return query(sh[lx].ls,sh[rx].ls,l,mid,k);
    54     else return query(sh[lx].rs,sh[rx].rs,mid+1,r,k-lz);
    55 }
    56 int main()
    57 {
    58     scanf("%d%d",&n,&m);
    59     for (int i=1;i<=n;i++)
    60       scanf("%d",&a[i]);
    61     for (int i=1;i<=n;i++) b[i]=a[i];
    62     sort(b+1,b+1+n);
    63     for (int i=1;i<=n;i++)
    64     {
    65         int pos=lower_bound(b+1,b+1+n,a[i])-b;
    66         tr[pos]=a[i];
    67         a[i]=pos;
    68     }
    69     root[0]=build(root[0],1,n);
    70     for (int i=1;i<=n;i++)
    71       root[i]=change(root[i-1],1,n,a[i]);
    72     while (m--)
    73     {
    74         int l,r,k;
    75         scanf("%d%d%d",&l,&r,&k);
    76         printf("%d
    ",tr[query(root[l-1],root[r],1,n,k)]);
    77     }
    78 }
    主席树
     1 #include <bits/stdc++.h>
     2 using namespace std;
     3 const int N=1e6+100;;
     4 int n,m,root[N],a[N];
     5 int cnt;
     6 struct node
     7 {
     8     int ls,rs,val;
     9 }sh[N*40];
    10 int build(int &x,int l,int r)
    11 {
    12     if (!x) x=++cnt;
    13     if (l==r)
    14     {
    15         sh[x].val=a[l];
    16         return x;
    17     }
    18     int mid=(l+r)>>1;
    19     sh[x].ls=build(sh[x].ls,l,mid);
    20     sh[x].rs=build(sh[x].rs,mid+1,r);
    21     return x;
    22 }
    23 int change(int x,int l,int r,int wh,int v)
    24 {
    25     int p=++cnt;
    26     sh[p]=sh[x];
    27     if (l==r)
    28     {
    29         sh[p].val=v;
    30         return p;
    31     }
    32     int mid=(l+r)>>1;
    33     if (wh<=mid) sh[p].ls=change(sh[x].ls,l,mid,wh,v);
    34     else sh[p].rs=change(sh[x].rs,mid+1,r,wh,v);
    35     return p;
    36 }
    37 int query(int x,int l,int r,int wh)
    38 {
    39     if (l==r) return sh[x].val;
    40     int mid=(l+r)>>1;
    41     if (wh<=mid) return query(sh[x].ls,l,mid,wh);
    42     else return query(sh[x].rs,mid+1,r,wh);
    43 }
    44 int main()
    45 {
    46     scanf("%d%d",&n,&m);
    47     for (int i=1;i<=n;i++)
    48       scanf("%d",&a[i]);
    49     root[0]=build(root[0],1,n);
    50     for (int i=1;i<=m;i++)
    51     {
    52         int ver,op,loc;
    53         scanf("%d%d%d",&ver,&op,&loc);
    54         if (op==1)
    55         {
    56             int v;
    57             scanf("%d",&v);
    58             root[i]=change(root[ver],1,n,loc,v);
    59         }
    60         if (op==2)
    61         {
    62             root[i]=root[ver];
    63             printf("%d
    ",query(root[ver],1,n,loc));
    64         }
    65     }
    66 }
    可持久化数组
     1 #include <bits/stdc++.h>
     2 using namespace std;
     3 const int N=1e5+100,M=2*1e5+100;
     4 int n,m,fa[N],root[M],cnt;
     5 struct node
     6 {
     7     int ls,rs,val,deep;
     8 }sh[N*40];
     9 int build(int &x,int l,int r)
    10 {
    11     if (!x) x=++cnt;
    12     if (l==r)
    13     {
    14         sh[x].val=fa[l];
    15         return x;
    16     }
    17     int mid=(l+r)>>1;
    18     sh[x].ls=build(sh[x].ls,l,mid);
    19     sh[x].rs=build(sh[x].rs,mid+1,r);
    20     return x;
    21 }
    22 int change(int x,int l,int r,int wh,int v)
    23 {
    24     int p=++cnt;
    25     sh[p]=sh[x];
    26     if (l==r)
    27     {
    28         sh[p].val=v;
    29         return p;
    30     }
    31     int mid=(l+r)>>1;
    32     if (wh<=mid) sh[p].ls=change(sh[x].ls,l,mid,wh,v);
    33     else sh[p].rs=change(sh[x].rs,mid+1,r,wh,v);
    34     return p;
    35 }
    36 void change_depth(int x,int l,int r,int wh)
    37 {
    38     if (l==r)
    39     {
    40         sh[x].deep++;
    41         return;
    42     }
    43     int mid=(l+r)>>1;
    44     if (wh<=mid) change_depth(sh[x].ls,l,mid,wh);
    45     else change_depth(sh[x].rs,mid+1,r,wh);
    46 }
    47 int query(int x,int l,int r,int wh,int kind)
    48 {
    49     if (l==r) return (kind==1)?sh[x].val:sh[x].deep;
    50     int mid=(l+r)>>1;
    51     if (wh<=mid) return query(sh[x].ls,l,mid,wh,kind);
    52     else return query(sh[x].rs,mid+1,r,wh,kind);
    53 }
    54 int find(int x,int &root)
    55 {
    56     int father=query(root,1,n,x,1);
    57     if (x==father) return x;
    58     return find(father,root);
    59 }
    60 int main()
    61 {
    62     scanf("%d%d",&n,&m);
    63     for (int i=1;i<=n;i++) fa[i]=i;
    64     root[0]=build(root[0],1,n);
    65     for (int i=1;i<=m;i++)
    66     {
    67         int op;
    68         scanf("%d",&op);
    69         if (op==1)
    70         {
    71             int a,b,Fa,Fb,da,db;
    72             scanf("%d%d",&a,&b);
    73             root[i]=root[i-1];
    74             Fa=find(a,root[i]);Fb=find(b,root[i]);
    75             da=query(root[i],1,n,Fa,0);db=query(root[i],1,n,Fb,0);
    76             if (Fa==Fb) continue;
    77             if (da>db) swap(Fa,Fb);
    78             root[i]=change(root[i],1,n,Fa,Fb);
    79             change_depth(root[i],1,n,Fb);
    80         }
    81         if (op==2)
    82         {
    83             int k;
    84             scanf("%d",&k);
    85             root[i]=root[k];
    86         }
    87         if (op==3)
    88         {
    89             int a,b,Fa,Fb;
    90             scanf("%d%d",&a,&b);
    91             root[i]=root[i-1];
    92             Fa=find(a,root[i]);
    93             Fb=find(b,root[i]);
    94             if (Fa==Fb) printf("1
    ");
    95             else printf("0
    ");
    96         }
    97     }
    98 }
    可持久化并查集

    4.数论分块

     1 #include <bits/stdc++.h>
     2 #define int long long
     3 using namespace std;
     4 int n,k;
     5 signed main()
     6 {
     7     scanf("%lld%lld",&n,&k);
     8     int ans=n*k;
     9     for (int i=1;i<=n;)
    10     {
    11         int t,j;
    12         t=k/i;
    13         j=(t!=0)?min(k/t,n):n;
    14         ans-=t*(i+j)*(j-i+1)/2;
    15         i=j+1;
    16     }
    17     printf("%lld
    ",ans);
    18 }
    数论分块

    5.树形背包

     1 #include <bits/stdc++.h>
     2 using namespace std;
     3 const int N=310;
     4 int n,m,s[N],dp[N][N],sz[N];
     5 vector <int> e[N];
     6 void dfs(int x)
     7 {
     8     dp[x][0]=0;
     9     for (int i=0;i<(int)e[x].size();i++)
    10     {
    11         int u=e[x][i];
    12         dfs(u);
    13         for (int j=m+1;j>0;j--)
    14         {
    15             for (int k=0;k<j;k++)
    16               dp[x][j]=max(dp[x][j],dp[x][j-k]+dp[u][k]);
    17         }
    18     }
    19 }
    20 int main()
    21 {
    22     scanf("%d%d",&n,&m);
    23     for (int i=1;i<=n;i++)
    24     {
    25         int k;
    26         scanf("%d%d",&k,&s[i]);
    27         dp[i][1]=s[i];
    28         e[k].push_back(i);
    29     }
    30     dfs(0);
    31     printf("%d
    ",dp[0][m+1]);
    32 }
    dfs合并
     1 #include <bits/stdc++.h>
     2 using namespace std;
     3 const int N=310;
     4 int n,m,s[N],dp[N][N],d[N],dfn[N],cnt;
     5 int nxt[N];
     6 vector <int> e[N];
     7 void dfs(int x)
     8 {
     9     dfn[x]=cnt++;
    10     for (int i=0;i<(int)e[x].size();i++)
    11     {
    12         int u=e[x][i];
    13         dfs(u);
    14     }
    15     nxt[dfn[x]]=cnt;
    16 }
    17 int main()
    18 {
    19     scanf("%d%d",&n,&m);
    20     for (int i=1;i<=n;i++)
    21     {
    22         int k;
    23         scanf("%d%d",&k,&s[i]);
    24         e[k].push_back(i);
    25     }
    26     dfs(0);
    27     memset(dp,-0x3f,sizeof(dp));
    28     memset(dp[0],0,sizeof(dp[0]));
    29     for (int i=1;i<=n;i++) d[dfn[i]]=s[i];
    30     for (int i=0;i<=n;i++)
    31     {
    32         for (int j=0;j<=min(i,m+1);j++)
    33         {
    34             dp[i+1][j+1]=max(dp[i+1][j+1],dp[i][j]+d[i]);
    35             dp[nxt[i]][j]=max(dp[nxt[i]][j],dp[i][j]);
    36         }
    37     }
    38     printf("%d
    ",dp[n+1][m+1]);
    39 }
    dfs序

    6.线段树合并

      1 #include <bits/stdc++.h>
      2 #define m_k make_pair
      3 using namespace std;
      4 const int N=100100;
      5 int n,m,tot,cnt,first[N],nxt[N*2],point[N*2];
      6 int fa[N][21],de[N],root[N],MAX,ans[N];
      7 vector <pair<int,int> > q[N];
      8 struct node
      9 {
     10     int ls,rs,MAX,id;
     11 }sh[N*50];
     12 void add_edge(int x,int y)
     13 {
     14     tot++;
     15     nxt[tot]=first[x];
     16     first[x]=tot;
     17     point[tot]=y;
     18 }
     19 void dfs(int x,int father)
     20 {
     21     fa[x][0]=father;
     22     for (int i=first[x];i!=-1;i=nxt[i])
     23     {
     24         int u=point[i];
     25         if (u==father) continue;
     26         de[u]=de[x]+1;
     27         dfs(u,x);
     28     }
     29 }
     30 int lca(int a,int b)
     31 {
     32     if (de[a]>de[b]) swap(a,b);
     33     for (int i=20;i>=0;i--)
     34     {
     35         if (de[fa[b][i]]>=de[a])
     36           b=fa[b][i];
     37     }
     38     if (a==b) return a;
     39     for (int i=20;i>=0;i--)
     40     {
     41         if (fa[a][i]!=fa[b][i])
     42         {
     43             a=fa[a][i];
     44             b=fa[b][i];
     45         }
     46     }
     47     return fa[a][0];
     48 }
     49 void pushup(int x)
     50 {
     51     int ls,rs;
     52     ls=sh[x].ls;rs=sh[x].rs;
     53     sh[x].MAX=max(sh[ls].MAX,sh[rs].MAX);
     54     if (sh[ls].MAX==sh[rs].MAX) sh[x].id=min(sh[ls].id,sh[rs].id);
     55     if (sh[ls].MAX<sh[rs].MAX) sh[x].id=sh[rs].id;
     56     if (sh[ls].MAX>sh[rs].MAX) sh[x].id=sh[ls].id;
     57 }
     58 void change(int &x,int l,int r,int co,int s)
     59 {
     60     if (!x) x=++cnt;
     61     if (l==r)
     62     {
     63         sh[x].MAX+=s;sh[x].id=co;
     64         return;
     65     }
     66     int mid=(l+r)>>1;
     67     if (co<=mid) change(sh[x].ls,l,mid,co,s);
     68     else change(sh[x].rs,mid+1,r,co,s);
     69     pushup(x);
     70 }
     71 int merge(int a,int b,int l,int r)
     72 {
     73     if (!a) return b;
     74     if (!b) return a;
     75     if (l==r)
     76     {
     77         sh[a].MAX+=sh[b].MAX;
     78         return a;
     79     }
     80     int mid=(l+r)>>1;
     81     sh[a].ls=merge(sh[a].ls,sh[b].ls,l,mid);
     82     sh[a].rs=merge(sh[a].rs,sh[b].rs,mid+1,r);
     83     pushup(a);
     84     return a;
     85 }
     86 void dfs1(int x)
     87 {
     88     for (int i=first[x];i!=-1;i=nxt[i])
     89     {
     90         int u=point[i];
     91         if (u==fa[x][0]) continue;
     92         dfs1(u);
     93     }
     94     root[x]=++cnt;
     95     for (int i=0;i<(int)q[x].size();i++)
     96       change(root[x],1,MAX,q[x][i].first,q[x][i].second);
     97     for (int i=first[x];i!=-1;i=nxt[i])
     98     {
     99         int u=point[i];
    100         if (u==fa[x][0]) continue;
    101         root[x]=merge(root[x],root[u],1,MAX);
    102     }
    103     ans[x]=sh[root[x]].MAX?sh[root[x]].id:0;
    104 }
    105 int main()
    106 {
    107     tot=-1;
    108     memset(nxt,-1,sizeof(nxt));
    109     memset(first,-1,sizeof(first));
    110     scanf("%d%d",&n,&m);
    111     for (int i=1;i<n;i++)
    112     {
    113         int x,y;
    114         scanf("%d%d",&x,&y);
    115         add_edge(x,y);
    116         add_edge(y,x);
    117     }
    118     dfs(1,1);
    119     for (int j=1;j<=20;j++)
    120     {
    121         for (int i=1;i<=n;i++)
    122           fa[i][j]=fa[fa[i][j-1]][j-1];
    123     }
    124     for (int i=1;i<=m;i++)
    125     {
    126         int a,b,c,l;
    127         scanf("%d%d%d",&a,&b,&c);
    128         l=lca(a,b);
    129         q[a].push_back(m_k(c,1));
    130         q[b].push_back(m_k(c,1));
    131         q[l].push_back(m_k(c,-1));
    132         if (l!=1) q[fa[l][0]].push_back(m_k(c,-1));
    133         MAX=max(MAX,c);
    134     }
    135     dfs1(1);
    136     for (int i=1;i<=n;i++) printf("%d
    ",ans[i]);
    137 }
    雨天的尾巴

    7.fhq_treap

      1 #include <bits/stdc++.h>
      2 using namespace std;
      3 const int MAXN=100100;
      4 int n,root,t;
      5 struct node
      6 {
      7     int val,key,si,son[2],g;
      8 }sh[MAXN];
      9 deque <int> q;
     10 int newnode(int v)
     11 {
     12     t++;
     13     sh[t].si=sh[t].g=1;
     14     sh[t].val=v;
     15     sh[t].key=rand();
     16     return t;
     17 }
     18 void pushup(int x)
     19 {
     20     sh[x].si=sh[x].g+sh[sh[x].son[0]].si+sh[sh[x].son[1]].si;
     21 }
     22 void split(int now,int k,int &x,int &y)
     23 {
     24     if (now==0)
     25     {
     26         x=y=0;
     27         return;
     28     }
     29     if (sh[now].val<=k)
     30     {
     31         x=now;
     32         split(sh[now].son[1],k,sh[now].son[1],y);
     33     }
     34     else
     35     {
     36         y=now;
     37         split(sh[now].son[0],k,x,sh[now].son[0]);
     38     }
     39     pushup(now);
     40 }
     41 int merge(int x,int y)
     42 {
     43     if (x==0)
     44       return y;
     45     if (y==0)
     46       return x;
     47     if (sh[x].key<sh[y].key)
     48     {
     49         sh[x].son[1]=merge(sh[x].son[1],y);
     50         pushup(x);
     51         return x;
     52     }
     53     else
     54     {
     55         sh[y].son[0]=merge(x,sh[y].son[0]);
     56         pushup(y);
     57         return y;
     58     }
     59 }
     60 int kth(int now,int k)
     61 {
     62     if (sh[sh[now].son[0]].si<k && k<=sh[sh[now].son[0]].si+sh[now].g)
     63       return now;
     64     else
     65     if (k<sh[sh[now].son[0]].si+sh[now].g)
     66       return kth(sh[now].son[0],k);
     67     else
     68       return kth(sh[now].son[1],k-sh[sh[now].son[0]].si-sh[now].g);
     69 }
     70 int find(int x)
     71 {
     72     q.clear();
     73     int cur;
     74     cur=root;
     75     while (sh[cur].son[x>sh[cur].val]!=0 && sh[cur].val!=x)
     76       q.push_back(cur),cur=sh[cur].son[x>sh[cur].val];
     77     q.push_back(cur);
     78     return cur;
     79 }
     80 void updata()
     81 {
     82     while (!q.empty())
     83     {
     84         pushup(q.back());
     85         q.pop_back();
     86     }
     87 }
     88 int main()
     89 {
     90     srand(time(0));
     91     root=0;
     92     scanf("%d",&n);
     93     for (int i=1;i<=n;i++)
     94     {
     95         int x,op;
     96         scanf("%d%d",&op,&x);
     97         if (op==1)
     98         {
     99             int cur=find(x);
    100             if (sh[cur].val==x)
    101             {
    102                 sh[cur].g++;
    103                 updata();
    104             }
    105             else
    106             {
    107                 int a,b;
    108                 split(root,x,a,b);
    109                 root=merge(merge(a,newnode(x)),b);
    110             }
    111         }
    112         if (op==2)
    113         {
    114             int cur=find(x);
    115             sh[cur].g--;
    116             updata();
    117             if (sh[cur].g==0)
    118             {
    119                 int a,b,c;
    120                 split(root,x,a,b);
    121                 split(a,x-1,a,c);
    122                 c=merge(sh[c].son[0],sh[c].son[1]);
    123                 root=merge(merge(a,b),c);
    124             }
    125         }
    126         if (op==3)
    127         {
    128             int a,b;
    129             split(root,x-1,a,b);
    130             printf("%d
    ",sh[a].si+1);
    131             root=merge(a,b);
    132         }
    133         if (op==4)
    134         {
    135             printf("%d
    ",sh[kth(root,x)].val);
    136         }
    137         if (op==5)
    138         {
    139             int a,b;
    140             split(root,x-1,a,b);
    141             printf("%d
    ",sh[kth(a,sh[a].si)].val);
    142             root=merge(a,b);
    143         }
    144         if (op==6)
    145         {
    146             int a,b;
    147             split(root,x,a,b);
    148             printf("%d
    ",sh[kth(b,1)].val);
    149             root=merge(a,b);
    150         }
    151     }
    152 }
    fhq_treap

    8.BSGS

     1 #include <bits/stdc++.h>
     2 #define int long long
     3 using namespace std;
     4 int p,b,n,sp;
     5 map <int,int> t;
     6 int m_pow(int a,int b)
     7 {
     8     int ans=1;
     9     while (b)
    10     {
    11         if (b&1) ans=(ans*a)%p;
    12         b>>=1;
    13         a=(a*a)%p;
    14     }
    15     return ans;
    16 }
    17 int inv(int x)
    18 {
    19     return m_pow(x,p-2);
    20 }
    21 int bsgs()
    22 {
    23     sp=sqrt(p);
    24     int x=1;
    25     for (int i=0;i<sp;i++)
    26     {
    27         t[x]=i;
    28         if (x==n) return i;
    29         x=(x*b)%p;
    30     }
    31     for (int i=2;i<=sp;i++)
    32     {
    33         int div=m_pow(b,sp*(i-1));
    34         div=inv(div);
    35         x=(n*div)%p;
    36         if (t[x]) return t[x]+sp*(i-1);
    37     }
    38     return -1;
    39 }
    40 signed main()
    41 {
    42     scanf("%lld%lld%lld",&p,&b,&n);
    43     if (n==0)
    44     {
    45         printf("1
    ");
    46         return 0;
    47     }
    48     int ans=bsgs();
    49     if (ans==-1) printf("no solution
    ");
    50     else printf("%lld
    ",ans);
    51 }
    BSGS

    9.exCRT/CRT

     1 #include <bits/stdc++.h>
     2 #define int long long
     3 using namespace std;
     4 const int N=1e5+100;
     5 int n,a[N],b[N];
     6 int mul(int a,int b,int mod)
     7 {
     8     bool bl=0;
     9     if (a<0) bl^=1;
    10     if (b<0) bl^=1;
    11     a=abs(a);b=abs(b);
    12     int ans=0;
    13     while (b)
    14     {
    15         if (b&1ll) ans=(ans+a)%mod;
    16         b>>=1ll;
    17         a=(a+a)%mod;
    18     }
    19     return (bl)?-ans:ans;
    20 }
    21 int gcd(int a,int b)
    22 {
    23     if (b==0) return a;
    24     else return gcd(b,a%b);
    25 }
    26 void exgcd(int a,int b,int &x,int &y)
    27 {
    28     if (b==0)
    29     {
    30         x=1;y=0;
    31         return;
    32     }
    33     exgcd(b,a%b,x,y);
    34     int z=x;
    35     x=y;y=z-(a/b)*y;
    36 }
    37 int lcm(int a,int b)
    38 {
    39     int g=gcd(a,b);
    40     return (a/g)*b;
    41 }
    42 int work(int a,int b,int c)
    43 {
    44     int g=gcd(a,b);
    45     a/=g;b/=g;c/=g;
    46     int x,y;
    47     exgcd(a,b,x,y);
    48     x=mul(x,c,b);x=(x%b+b)%b;
    49     return x;
    50 }
    51 signed main()
    52 {
    53     scanf("%lld",&n);
    54     for (int i=1;i<=n;i++)
    55       scanf("%lld%lld",&a[i],&b[i]);
    56     for (int i=2;i<=n;i++)
    57     {
    58         int x=work(a[1],a[i],b[i]-b[1]);
    59         int na=a[1];
    60         a[1]=lcm(a[1],a[i]);
    61         b[1]=(mul(na,x,a[1])+b[1])%a[1];
    62         // b[1]=a[1]*x+b[1];
    63     }
    64     printf("%lld
    ",b[1]);
    65 }
    CRT

    10.Miller Robin素数测试

     1 #include <bits/stdc++.h>
     2 #define int long long
     3 using namespace std;
     4 int n;
     5 int p[8]={2,3,5,7,11,13,17,47};
     6 int mul(int a,int b,int mod)
     7 {
     8     int ans=0;
     9     while (b)
    10     {
    11         if (b&1) ans=(ans+a)%mod;
    12         b>>=1;
    13         a=(a+a)%mod;
    14     }
    15     return ans;
    16 }
    17 int m_pow(int a,int b,int mod)
    18 {
    19     int ans=1;
    20     while (b)
    21     {
    22         if (b&1) ans=mul(ans,a,mod);
    23         b>>=1;
    24         a=mul(a,a,mod);
    25     }
    26     return ans;
    27 }
    28 bool miller_robin(int n,int a)
    29 {
    30     int d,r;
    31     d=n-1;r=0;
    32     while (d%2==0)
    33     {
    34         d>>=1;
    35         r++;
    36     }
    37     int now=m_pow(a,d,n);
    38     if (now==1) return true;
    39     for (int i=0;i<r;i++)
    40     {
    41         if (now==n-1) return true;
    42         now=mul(now,now,n);
    43     }
    44     return false;
    45 }
    46 bool check(int n)
    47 {
    48     if (n<2) return false;
    49     for (int i=0;i<8;i++)
    50     {
    51         if (n==p[i]) return true;
    52         if (n%p[i]==0) return false;
    53         if (!miller_robin(n,p[i]) && n>p[i]) return false;
    54     }
    55     return true;
    56 }
    57 signed main()
    58 {
    59     scanf("%lld",&n);
    60     if (check(n)) printf("Prime
    ");
    61     else printf("Not Prime
    ");
    62 }
    Miller Robin
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  • 原文地址:https://www.cnblogs.com/huangchenyan/p/12221910.html
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