UVA 11996 splay

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题意：给一个序列，还有四个操作，1是在第p个字符后面加入c，2是删除第p个字符，3是区间反转，4是询问p1和p2开头的字符串的lcp

思路：除了正常的splay以外，需要多维护一个哈希值，然后二分长度比较哈希值即可

#include <stdio.h>#include <string.h>#include <stdlib.h>#include <iostream>#include <algorithm>using namespace std;typedef long long ll;typedef unsigned long long ull;const int inf=0x3f3f3f3f;const ll INF=0x3f3f3f3f3f3f3f3fll;const int js=163;const int maxn=400010;int pre[maxn],ch[maxn][2],size[maxn],root,tot1;//父节点，左右孩子，子树规模，根节点，节点数量int key[maxn],flag[maxn],rev[maxn],m[maxn];//该点的值，懒惰标记int a[maxn],n,q;int s[maxn],tot2;ull Hash[maxn][2],p[maxn];char str[maxn];void treaval(int x){//debug部分    if(x){        treaval(ch[x][0]);        printf("结点%2d:左儿子 %2d 右儿子 %2d 父结点 %2d size=%2d,key=%2d add=%2d\n",x,ch[x][0],ch[x][1],pre[x],size[x],key[x],flag[x]);        treaval(ch[x][1]);    }}void debug(){    printf("root:%d\n",root);treaval(root);}void newnode(int &r,int fa,int k){    if(tot2) r=s[tot2--];    else r=++tot1;    pre[r]=fa;size[r]=1;key[r]=m[r]=k;flag[r]=0;rev[r]=0;    Hash[r][0]=Hash[r][1]=k;    ch[r][0]=ch[r][1]=0;}void update_rev(int r){    if(r==0) return ;    swap(ch[r][0],ch[r][1]);    swap(Hash[r][0],Hash[r][1]);    rev[r]^=1;}void update_add(int r,int val){    if(r==0) return ;    flag[r]+=val;    key[r]+=val;    m[r]+=val;}void pushup(int r){    size[r]=size[ch[r][0]]+size[ch[r][1]]+1;    int len=size[ch[r][0]];    Hash[r][0]=Hash[ch[r][0]][0]+key[r]*p[len]+Hash[ch[r][1]][0]*p[len+1];    len=size[ch[r][1]];    Hash[r][1]=Hash[ch[r][1]][1]+key[r]*p[len]+Hash[ch[r][0]][1]*p[len+1];    m[r]=key[r];    if(ch[r][0]) m[r]=min(m[r],m[ch[r][0]]);    if(ch[r][1]) m[r]=min(m[r],m[ch[r][1]]);}void pushdown(int r){    if(rev[r]){        update_rev(ch[r][0]);        update_rev(ch[r][1]);        rev[r]=0;    }    if(flag[r]){        update_add(ch[r][0],flag[r]);        update_add(ch[r][1],flag[r]);        flag[r]=0;    }}void buildtree(int &x,int l,int r,int fa){    if(l>r) return ;    int mid=(l+r)>>1;    newnode(x,fa,str[mid]-'0');    buildtree(ch[x][0],l,mid-1,x);    buildtree(ch[x][1],mid+1,r,x);    pushup(x);}void init(){    root=tot1=tot2=0;    ch[root][0]=ch[root][1]=pre[root]=size[root]=flag[root]=0;    key[root]=0;m[root]=inf;    newnode(root,0,inf);    newnode(ch[root][1],root,inf);    buildtree(ch[ch[root][1]][0],1,n,ch[root][1]);    pushup(ch[root][1]);pushup(root);}void Rotate(int x,int kind){    int y=pre[x];    pushdown(y);pushdown(x);    ch[y][!kind]=ch[x][kind];    pre[ch[x][kind]]=y;    if(pre[y]) ch[pre[y]][ch[pre[y]][1]==y]=x;    pre[x]=pre[y];    ch[x][kind]=y;pre[y]=x;    pushup(y);}void splay(int r,int goal){    pushdown(r);    while(pre[r]!=goal){        if(pre[pre[r]]==goal){            pushdown(pre[r]);pushdown(r);            Rotate(r,ch[pre[r]][0]==r);        }else{            pushdown(pre[pre[r]]);pushdown(pre[r]);            pushdown(r);            int y=pre[r];            int kind=ch[pre[y]][0]==y;            if(ch[y][kind]==r) Rotate(r,!kind),Rotate(r,kind);            else Rotate(y,kind),Rotate(r,kind);        }    }    pushup(r);    if(goal==0) root=r;}int get_kth(int r,int k){    pushdown(r);    int t=size[ch[r][0]]+1;    if(t==k) return r;    if(t>k) return get_kth(ch[r][0],k);    else return get_kth(ch[r][1],k-t);}int get_min(int r){    pushdown(r);    while(ch[r][0]){        r=ch[r][0];        pushdown(r);    }    return r;}int get_max(int r){    pushdown(r);    while(ch[r][1]){        r=ch[r][1];        pushdown(r);    }    return r;}void add(int l,int r,int val){    splay(get_kth(root,l),0);    splay(get_kth(root,r+2),root);    update_add(ch[ch[root][1]][0],val);    pushup(ch[root][1]);    pushup(root);}void Reverse(int l,int r){    splay(get_kth(root,l),0);    splay(get_kth(root,r+2),root);    update_rev(ch[ch[root][1]][0]);    pushup(ch[root][1]);pushup(root);}void Insert(int x,int p){    splay(get_kth(root,x+1),0);    splay(get_kth(root,x+2),root);    newnode(ch[ch[root][1]][0],ch[root][1],p);    pushup(ch[root][1]);pushup(root);}void erase(int r){    if(r){        s[++tot2]=r;        erase(ch[r][0]);        erase(ch[r][1]);    }}void Delete(int x){    splay(get_kth(root,x),0);    splay(get_kth(root,x+2),root);    erase(ch[ch[root][1]][0]);pre[ch[ch[root][1]][0]]=0;    ch[ch[root][1]][0]=0;    pushup(ch[root][1]);pushup(root);}int query_min(int l,int r){    splay(get_kth(root,l),0);    splay(get_kth(root,r+2),root);    return m[ch[ch[root][1]][0]];}void pri(int x){    if(x==0) return ;    pushdown(x);    if(ch[x][0]) pri(ch[x][0]);    if(key[x]>=0&&key[x]<=1) printf("%d\n",key[x]);    if(ch[x][1]) pri(ch[x][1]);}void Revolve(int l,int r){    splay(get_kth(root,l),0);    splay(get_kth(root,r+2),root);    int tmp=ch[ch[root][1]][0];    ch[ch[root][1]][0]=0;    pushup(ch[root][1]);pushup(root);    int len=r-l+1;    len=n-len+1;    splay(get_kth(root,len),0);    splay(get_kth(root,len+1),root);    ch[ch[root][1]][0]=tmp;    pre[ch[ch[root][1]][0]]=ch[root][1];    pushup(ch[root][1]);pushup(root);}bool judge(int x,int y,int len){    ull xx,yy;    splay(get_kth(root,x),0);    if(size[ch[root][1]]-1<len) return 0;    splay(get_kth(root,x+len+1),root);    int tmp=ch[ch[root][1]][0];    xx=Hash[tmp][0];    pushup(ch[root][1]);pushup(root);    splay(get_kth(root,y),0);    if(size[ch[root][1]]-1<len) return 0;    splay(get_kth(root,y+len+1),root);    tmp=ch[ch[root][1]][0];    yy=Hash[tmp][0];    pushup(ch[root][1]);pushup(root);    if(xx==yy) return 1;    else return 0;}int slove(int x,int y){    int le=1,ri=size[root]-1;    if(!judge(x,y,1)) return 0;    while(ri-le>1){        int mid=(le+ri)>>1;        if(judge(x,y,mid)) le=mid;        else ri=mid;    }    return le;}int main(){    p[0]=1;    for(int i=1;i<maxn;i++) p[i]=p[i-1]*js;    int x,y,op;    while(scanf("%d%d",&n,&q)!=-1){        scanf("%s",str+1);        init();//        debug();        while(q--){            scanf("%d",&op);            if(op==1){                scanf("%d%d",&x,&y);                if(x==0) Insert(0,y);                else Insert(x,y);            }else if(op==2){                scanf("%d",&x);                Delete(x);            }else if(op==3){                scanf("%d%d",&x,&y);                Reverse(x,y);            }else{                scanf("%d%d",&x,&y);                printf("%d\n",slove(x,y));            }//            debug();        }    }    return 0;}