各种模板

为了避免忘掉各种板子或者被网上其他看不懂的模板辣眼睛，就有了这些简单的模板

auto simpleson
Adaptive Simpson

#include<cstring>#include<cstdio>#include<algorithm>#include<iostream>#include<cmath>#include<queue>using namespace std;typedef long long ll;#define rep(i,l,r) for(int i=l;i<=r;++i)#define rpe(i,r,l) for(int i=r;i>=l;--i)#define rpp(i,x,e,head) for(int i=head[x];~i;i=e[i].next)#define dyes cerr<<"yes"<<endl#define debug(x) cerr<<#x<<"="<<x<<endl;#define pts puts("")inline int read(){    int f=1,x=0;char ch;    do{ch=getchar();if(ch=='-')f=-1;}while(ch<'0'||ch>'9');    do{x=x*10+ch-'0';ch=getchar();}while(ch>='0'&&ch<='9');    return f*x;}const int inf=1000000000;template <class T> inline void chmax(T &a,T b){if(a<b) a=b;}template <class T> inline void chmin(T &a,T b){if(a>b) a=b;}inline ll max(ll a,ll b){return a<b ? a:b;}inline void swap(int &a,int &b){int c=a;a=b;b=c;}using namespace std;inline long double f(long double x){    return x*x+3*x+6.; }inline long double simple(long double a,long double b){    return (b-a)/6.*(f(a)+4.*f((a+b)/2.)+f(b));}// a,b eps and now integral == Ainline long double asr(long double a,long double b,long double eps,long double A){    double c=a+(b-a)/2.;    double L=simple(a,c),R=simple(c,b);    if(fabs(L+R-A)<=15*eps) return L+R+(L+R-A)/15.;    return asr(a,c,eps/2.,L)+asr(c,b,eps/2.,R);}inline long double asr(long double a,long double b){    return asr(a,b,1e-2,simple(a,b));}long double x,y;

Kmp

#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>using namespace std;#define rep(i,l,r) for(int i=l;i<=r;++i)const int N=1e6+10;int nxt[N];char a[N],b[N];inline void getnxt(char *p){    nxt[0]=-1;int j=-1;    int n=strlen(p+1);    for(int i=1;i<=n;nxt[i++]=++j)        while(~j&&p[j+1]!=p[i]) j=nxt[j];}inline void match(char *s,char *p){    int j=0;int n=strlen(s+1),m=strlen(p+1);    rep(i,1,n){        while(~j&&s[i]!=p[j+1]) j=nxt[j];        if(++j==m) printf("%d\n",i-m+1);    }}int main(){    scanf("%s%s",a+1,b+1);    getnxt(b);match(a,b);    int m=strlen(b+1);    rep(i,1,m)printf("%d ",nxt[i]);    return 0;}

LCT
(弹飞绵羊)

#include<bits/stdc++.h>using namespace std;#define rep(i,l,r) for(register int i=l;i<=r;++i)#define rpe(i,r,l) for(register int i=r;i>=l;--i)#define rpp(i,x,e,head) for(register int i=head[x];~i;i=e[i].next)#define dyes cerr<<"yes"<<endltemplate <class Type> inline void read(Type &cur){    Type ret=0,flag=1;    char ch=getchar();    while(ch<'0'||ch>'9'){        if(ch=='-')            flag=-1;        ch=getchar();    }    while(ch>='0'&&ch<='9'){        ret=ret*10+ch-'0';        ch=getchar();    }    cur=ret*flag;}const int maxn=2e5+10;struct Node;inline void swap(Node *&a,Node *&b){    Node *c=b;    b=a;    a=c;}struct Node{    int sz,rev;    Node *fa,*ch[2];    Node(){sz=1;rev=0;fa=ch[0]=ch[1]=NULL;}    inline void up(){        sz=1;        if(ch[0]) sz+=ch[0]->sz;        if(ch[1]) sz+=ch[1]->sz;    }    inline void push(){        if(rev){            rev=0;swap(ch[0],ch[1]);            if(ch[0])                ch[0]->rev=!ch[0]->rev;            if(ch[1])                ch[1]->rev=!ch[1]->rev;        }    }}*pool[maxn<<1],*tmp[maxn];int top=0;inline void initpool(){rep(i,0,maxn-1) pool[i]=new Node();}inline void del(Node *p){pool[--top]=p;p=NULL;}inline void newnode(Node *&p,Node *fa){p=pool[top++];*p=Node();p->fa=fa;}int to[maxn];int n,m;struct LCT{    Node *node[maxn];    inline void init(int n){        rep(i,1,n) newnode(node[i],NULL);    }    inline int get(Node *p){        return p->fa->ch[1]==p;    }    inline int isroot(Node *p){        return !p->fa||(p->fa->ch[0]!=p&&p->fa->ch[1]!=p);    }    inline void rotate(Node *p){        int d=get(p);Node *fa=p->fa;        fa->ch[d]=p->ch[d^1];        if(p->ch[d^1]) p->ch[d^1]->fa=fa;        p->fa=fa->fa;        if(!isroot(fa)) p->fa->ch[get(fa)]=p;        fa->fa=p;p->ch[d^1]=fa;fa->up();p->up();    }    inline void splay(Node *p){        int pos=0;        for(Node *t=p;;t=t->fa){            tmp[++pos]=t;            if(isroot(t))                break;        }        rpe(i,pos,1) tmp[i]->push();        for(;!isroot(p);rotate(p)){            if(!isroot(p->fa))                rotate(get(p)==get(p->fa) ? p->fa:p);        }        p->up();    }    inline void access(Node *p){        for(Node *pre=NULL;p;pre=p,p=p->fa)            splay(p),p->ch[1]=pre,p->up();    }    inline void makeroot(Node *p){access(p);splay(p);p->rev^=1;}    inline void cut(Node *x,Node *y){        makeroot(x);access(y);splay(y);        x->fa=y->ch[0]=NULL;y->up();    }    inline void link(Node *x,Node *y){        makeroot(x);x->fa=y;    }    inline void link(int x,int y){        node[x]->fa=node[y];    }    inline void op1(int x){        makeroot(node[n+1]);        access(node[x]);        splay(node[x]);        printf("%d\n",node[x]->ch[0]->sz);    }    inline void op2(int x,int y){        cut(node[x],node[min(x+to[x],n+1)]);        to[x]=y;        link(node[x],node[min(x+to[x],n+1)]);    }}lct;int main(int argc,const char * argv[]){    read(n);    initpool();    lct.init(n+1);    rep(i,1,n){        read(to[i]);        lct.link(i,min(i+to[i],n+1));    }    read(m);    rep(i,1,m){        int op;        read(op);        if(op==1){            int x;read(x);            lct.op1(x+1);        }else{            int x,y;read(x);read(y);            lct.op2(x+1,y);        }    }    return 0;};    init_pool();    lct.init(n+1);    rep(i,1,n){        read(to[i]);        lct.link(i,min(i+to[i],n+1));    }    int m,op;    read(m);    rep(i,1,m){        read(op);        if(op==1){            int x;read(x);            lct.op1(x+1);        }else{            int x,y;            read(x);read(y);            lct.op2(++x,y);        }    }    return 0;}

链剖
(zjoi2008 COT)

#include<bits/stdc++.h>using namespace std;#define rep(i,l,r) for(int i=l;i<=r;i++)#define dyes cerr<<"yes"<<endltemplate <class Type> inline void read(Type &cur){    Type ret=0,flag=1;    char ch=getchar();    while(ch<'0'||ch>'9'){        if(ch=='-')            flag=-1;        ch=getchar();    }    while(ch>='0'&&ch<='9'){        ret=ret*10+ch-'0';        ch=getchar();    }    cur=ret*flag;}const int maxn=3e4+10;const int maxm=2e5+10;struct node{    int next,to;}e[maxm<<1];int head[maxn],cnt;inline void add(int u,int v){    e[cnt].to=v;    e[cnt].next=head[u];    head[u]=cnt++;}int n,q;int val[maxn];int dep[maxn],size[maxn],son[maxn],fa[maxn];inline void dfs1(int x,int from){    son[x]=0;    size[x]=1;    fa[x]=from;    for(int i=head[x];~i;i=e[i].next){        if(e[i].to!=from){            dep[e[i].to]=dep[x]+1;            dfs1(e[i].to,x);            size[x]+=size[e[i].to];            if(size[son[x]]<size[e[i].to])                son[x]=e[i].to;        }    }}int top[maxn],id[maxn],pre[maxn],tot;inline void dfs2(int x,int tp){    top[x]=tp;    id[x]=++tot;    pre[id[x]]=x;    if(son[x])        dfs2(son[x],tp);    for(int i=head[x];~i;i=e[i].next){        if(e[i].to!=fa[x]&&e[i].to!=son[x]){            dfs2(e[i].to,e[i].to);        }    }}struct seg{    int l,r,sum,max;}sum[maxn<<2];inline void upd(int cur){    sum[cur].sum=sum[cur<<1].sum+sum[cur<<1|1].sum;    sum[cur].max=max(sum[cur<<1].max,sum[cur<<1|1].max);}inline void build(int cur,int l,int r){    sum[cur].l=l;sum[cur].r=r;    if(l==r){        sum[cur].sum=sum[cur].max=val[pre[l]];        return;    }    int mid=(l+r)>>1;    build(cur<<1,l,mid);    build(cur<<1|1,mid+1,r);    upd(cur);}inline void change(int cur,int x,int y){    if(sum[cur].l==x&&sum[cur].r==x){        sum[cur].sum=sum[cur].max=y;        return;    }    int mid=(sum[cur].l+sum[cur].r)>>1;    if(x<=mid)        change(cur<<1,x,y);    if(x>mid)        change(cur<<1|1,x,y);    upd(cur);}inline int ask_max(int cur,int l,int r){    int L=sum[cur].l,R=sum[cur].r;    if(l<=L&&r>=R){        return sum[cur].max;    }    int mid=(L+R)>>1;    int m1=-0x3f3f3f3f,m2=-0x3f3f3f3f;    if(l<=mid)        m1=ask_max(cur<<1,l,r);    if(r>mid)        m2=ask_max(cur<<1|1,l,r);    return max(m1,m2);}inline int ask_sum(int cur,int l,int r){    int L=sum[cur].l,R=sum[cur].r;    if(l<=L&&r>=R){        return sum[cur].sum;    }    int mid=(L+R)>>1;    int m1=0,m2=0;    if(l<=mid)        m1=ask_sum(cur<<1,l,r);    if(r>mid)        m2=ask_sum(cur<<1|1,l,r);    return m1+m2;}inline int find_max(int x,int y){    int f1=top[x],f2=top[y];    int tmp=-0x3f3f3f3f;    while(f1!=f2){        if(dep[f1]<dep[f2])            swap(f1,f2),swap(x,y);        tmp=max(tmp,ask_max(1,id[f1],id[x]));        x=fa[f1];f1=top[x];    }    if(dep[x]>dep[y])        swap(x,y);    return max(tmp,ask_max(1,id[x],id[y]));}inline int find_sum(int x,int y){    int f1=top[x],f2=top[y];    int tmp=0;    while(f1!=f2){        if(dep[f1]<dep[f2]){            swap(f1,f2);            swap(x,y);        }        tmp+=ask_sum(1,id[f1],id[x]);        x=fa[f1];f1=top[x];    }    if(dep[x]>dep[y])        swap(x,y);    return tmp+ask_sum(1,id[x],id[y]);}char s[66];int main(int argc,const char * argv[]){    memset(head,-1,sizeof(head));    read(n);    int x,y;    rep(i,1,n-1){        read(x);read(y);        add(x,y);        add(y,x);    }    rep(i,1,n)        read(val[i]);    dfs1(1,0);    dfs2(1,1);    build(1,1,n);    read(q);    rep(i,1,q){        scanf("%s",&s);        read(x);read(y);        if(s[0]=='C'){            change(1,id[x],y);        }        if(s[0]=='Q'){            if(s[1]=='M'){                printf("%d\n",find_max(x,y));            }            if(s[1]=='S'){                printf("%d\n",find_sum(x,y));            }        }    }    return 0;}

点分治
自带大常数（O2保平安

#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>using namespace std;#define rep(i,l,r) for(int i=l;i<=r;i++)const int maxn=1e4+10;const int maxk=1e7+10;int n,m,head[maxn],cnt,k;inline int read(){    int ret=0,flag=1;    char ch=getchar();    while(ch<'0'||ch>'9'){        if(ch=='-')            flag=-1;        ch=getchar();    }    while(ch>='0'&&ch<='9'){        ret=ret*10+ch-'0';        ch=getchar();    }    return ret*flag;}struct node{    int next,to,w;}e[maxn<<1];inline void add(int u,int v,int w){    e[cnt].to=v;    e[cnt].w=w;    e[cnt].next=head[u];    head[u]=cnt++;}int tot;int vis[maxn];int dep[maxn];int root,size[maxn],num[maxk];const int inf=1e9+10;int minn;inline void getroot(int x,int fa,int N){    size[x]=1;    int tmp=0;    for(int i=head[x];~i;i=e[i].next){        if(e[i].to^fa&&!vis[e[i].to]){            getroot(e[i].to,x,N);            size[x]+=size[e[i].to];            tmp=max(tmp,size[e[i].to]);        }    }    tmp=max(tmp,N-size[x]);    if(tmp<minn)        minn=tmp,root=x;}inline void getdep(int x,int fa,int d){    dep[++tot]=d;    for(int i=head[x];~i;i=e[i].next){        if(e[i].to!=fa&&!vis[e[i].to]){            getdep(e[i].to,x,d+e[i].w);        }    }}inline void calc(int cur,int ind,int ini){    tot=0;    getdep(cur,cur,0);    rep(i,1,tot)    rep(j,1,tot)    if(ind&&dep[i]+dep[j]<maxk)        num[dep[i]+dep[j]]++;    else if(dep[i]+dep[j]+ini<maxk)        num[dep[i]+dep[j]+ini]--;}inline void work(int x){    calc(x,1,0);    vis[x]=1;    for(int i=head[x];~i;i=e[i].next){        if(!vis[e[i].to]){            calc(e[i].to,0,e[i].w*2);            root=0;minn=inf;            getroot(e[i].to,x,size[e[i].to]);            //cerr<<root<<endl;            work(root);        }    }}int x,y,z;int main(int argc,const char * argv[]){    memset(head,-1,sizeof(head));    n=read(),m=read();    rep(i,1,n-1)        x=read(),y=read(),z=read(),add(x,y,z),add(y,x,z);    minn=inf;    getroot(1,1,n);    //cerr<<root<<endl;    work(root);    rep(i,1,m){        k=read();        if(num[k])            puts("AYE");        else            puts("NAY");    }    return 0;}

Tarjan缩点，在DAG上的dp(我居然第一次把出栈条件打错了)

#include<bits/stdc++.h>using namespace std;int n,m;const int maxn=1e4+10;const int maxm=1e5+10;inline int read(){    int ret=0,flag=1;    char ch=getchar();    while(ch<'0'||ch>'9'){        if(ch=='-')            flag=-1;        ch=getchar();    }    while(ch>='0'&&ch<='9'){        ret=ret*10+ch-'0';        ch=getchar();    }    return ret*flag;}struct node{    int u;    int next,to;}a[maxm<<1],e[maxm<<1];int w[maxn];int head1[maxn],tot;inline void ins(int u,int v){    a[tot].u=u;    a[tot].to=v;    a[tot].next=head1[u];    head1[u]=tot++;}int head[maxn],cnt;inline void add(int u,int v){    e[cnt].to=v;    e[cnt].next=head[u];    head[u]=cnt++;}int dfn[maxn],low[maxn],dfs_num;int color[maxn],col_num;bool vis[maxn];stack<int> s;int ans;int val[maxn];int f[maxn];int in[maxn];int gt[maxn];queue<int> q;inline void tarjan(int x){    dfn[x]=++dfs_num;    low[x]=dfs_num;    vis[x]=true;    s.push(x);    for(int i=head1[x];~i;i=a[i].next){        if(!dfn[a[i].to]){            tarjan(a[i].to);            low[x]=min(low[x],low[a[i].to]);        }else if(vis[a[i].to]){            low[x]=min(low[x],dfn[a[i].to]);        }    }    if(low[x]==dfn[x]){        color[x]=++col_num;        vis[x]=false;        val[col_num]+=w[x];        while(!s.empty()){            if(s.top()==x)                break;            color[s.top()]=col_num;            vis[s.top()]=false;            val[col_num]+=w[s.top()];            s.pop();        }        s.pop();    }}inline void topo(){    while(!q.empty()){        int cur=q.front();q.pop();        for(int i=head[cur];~i;i=e[i].next){            int to=e[i].to;            gt[to]=max(gt[to],gt[cur]+val[to]);            ans=max(ans,gt[to]);            in[to]--;            if(!in[to])                q.push(to);        }    }}int main(int argc,const char * argv[]){    memset(head,-1,sizeof(head));    memset(head1,-1,sizeof(head1));    n=read();m=read();    for(int i=1;i<=n;i++){        w[i]=read();    }    int x,y;    for(int i=1;i<=m;i++){        x=read();y=read();        ins(x,y);    }    //cout<<"yes"<<endl;    for(int i=1;i<=n;i++){        if(!dfn[i]){            tarjan(i);        }    }    for(int i=1;i<=col_num;i++){        ans=max(ans,val[i]);    }    for(int i=1;i<=m;i++){        if(color[a[i].u]!=color[a[i].to]){            add(color[a[i].u],color[a[i].to]);            in[color[a[i].to]]++;        }    }    for(int i=1;i<=col_num;i++){        if(in[i]==0){            q.push(i);            gt[i]+=val[i];            ans=max(ans,gt[i]);        }    }    topo();    printf("%d\n",ans);    return 0;}

Splay(数组版)
双旋大法好~

#include<cstdio>#include<cstring>#include<algorithm>#include<iostream>using namespace std;const int maxn=1e5+10;inline int read(){    int ret=0,flag=1;    char ch=getchar();    while(ch<'0'||ch>'9'){        if(ch=='-')            flag=-1;        ch=getchar();    }    while(ch>='0'&&ch<='9'){        ret=ret*10+ch-'0';        ch=getchar();    }    return ret*flag;}int ch[maxn][2],f[maxn],size[maxn],cnt[maxn],key[maxn];int sz,root;inline void clear(int x){    ch[x][0]=ch[x][1]=f[x]=size[x]=cnt[x]=key[x]=0;}inline bool get(int x){    return ch[f[x]][1]==x;}inline void upd(int x){    if(x){        size[x]=cnt[x];        if(ch[x][0]) size[x]+=size[ch[x][0]];        if(ch[x][1]) size[x]+=size[ch[x][1]];    }}inline void rotate(int x){    int old=f[x],oldf=f[old],d=get(x);    ch[old][d]=ch[x][d^1]; f[ch[old][d]]=old;    ch[x][d^1]=old; f[old]=x;    f[x]=oldf;    if(oldf)        ch[oldf][ch[oldf][1]==old]=x;    upd(old);upd(x);}inline void splay(int x){    for(int fa;fa=f[x];rotate(x))        if(f[fa])            rotate((get(x)==get(fa))? fa:x);    root=x;}inline void insert(int x){    if(root==0){        sz++;        ch[sz][0]=ch[sz][1]=f[sz]=0;        root=sz;        size[sz]=cnt[sz]=1;        key[sz]=x;        return;    }    int now=root,fa=0;    while(1){        if(x==key[now]){            cnt[now]++;            upd(now);upd(fa);splay(now);            break;        }        fa=now;        now=ch[now][key[now]<x];        if(now==0){            sz++;            ch[sz][0]=ch[sz][1]=0;            f[sz]=fa;            size[sz]=cnt[sz]=1;            key[sz]=x;            ch[fa][key[fa]<x]=sz;            upd(fa);            splay(sz);            break;        }    }}inline int find(int x){    int now=root,ans=0;    while(1){        if(x<key[now])            now=ch[now][0];        else{            ans+=(ch[now][0]?size[ch[now][0]]:0);            if(x==key[now]){                splay(now);                return ans+1;            }            ans+=cnt[now];            now=ch[now][1];        }    }}inline int findx(int x){    int now=root;    while(1){        if(ch[now][0]&&x<=size[ch[now][0]])            now=ch[now][0];        else{            int tmp=(ch[now][0]? size[ch[now][0]]:0)+cnt[now];            if(x<=tmp) return key[now];            x-=tmp;now=ch[now][1];        }    }}inline int pre(){    int now=ch[root][0];    while(ch[now][1])        now=ch[now][1];    return now;}inline int nxt(){    int now=ch[root][1];    while(ch[now][0])        now=ch[now][0];    return now;}inline void del(int x){    int rk=find(x);    if(cnt[root]>1){        cnt[root]--;upd(root);return;    }    if(!ch[root][0]&&!ch[root][1]){        clear(root);root=0;return;    }    if(!ch[root][0]){        int oldroot=root;root=ch[root][1];f[root]=0;clear(oldroot);return;    }    else if(!ch[root][1]){        int oldroot=root;root=ch[root][0];f[root]=0;clear(oldroot);return;    }    int leftbig=pre();int oldroot=root;    splay(leftbig);    ch[root][1]=ch[oldroot][1];    f[ch[oldroot][1]]=root;    clear(oldroot);    upd(root);}int main(int argc,const char * argv[]){    int n,opt,x;    n=read();    for (int i=1;i<=n;++i){        opt=read();x=read();        switch(opt){            case 1: insert(x); break;            case 2: del(x); break;            case 3: printf("%d\n",find(x)); break;            case 4: printf("%d\n",findx(x)); break;            case 5: insert(x); printf("%d\n",key[pre()]); del(x); break;            case 6: insert(x); printf("%d\n",key[nxt()]); del(x); break;        }    }    return 0;}