bzoj1269&&1507

  1 #include<cstdio>
  2 #include<cstring>
  3 #include<cmath>
  4 #include<cstdlib>
  5 #include<ctime>
  6 #include<algorithm>
  7 #include<iostream>
  8 #define clr(a,x) memset(a,x,sizeof(a))
  9 #define rep(i,l,r) for(int i=l;i<(r);i++)
 10 using namespace std;
 11 typedef long long ll;
 12 const int maxn=2000009;
 13 int n,now=0;
 14 char a[maxn];
 15 struct node*null,*root;
 16 struct node{
 17     int s;
 18     char c;
 19     node*ch[2];
 20     bool rev;
 21     node(){
 22         s=0;c=rev=0;ch[0]=ch[1]=null;
 23     }
 24     inline int cmp(int k){
 25         k-=ch[0]->s;
 26         if(k==1) return -1;
 27         return k<=0?0:1; 
 28     }
 29     inline void maintain(){
 30         s=ch[0]->s+ch[1]->s+1;
 31     }
 32     inline void Rev(){
 33         rev^=1;
 34         swap(ch[0],ch[1]);
 35     }
 36     inline void pushdown(){
 37         if(rev){
 38             if(ch[0]!=null) ch[0]->Rev();
 39             if(ch[1]!=null) ch[1]->Rev();
 40             rev=0;
 41         }
 42     }
 43 };
 44 inline void rot(node*&o,int d){        
 45     o->pushdown();
 46     node*p=o->ch[d^1];
 47     p->pushdown();
 48     o->ch[d^1]=p->ch[d];p->ch[d]=o;
 49     o->maintain();p->maintain();
 50     o=p;
 51 }
 52 inline void splay(node*&o,int k){
 53     o->pushdown();
 54     int d=o->cmp(k);//cout<<o->ch[0]->s<<endl;
 55     if(d==-1) return;
 56     if(d==1) k-=o->ch[0]->s+1;
 57     node*p=o->ch[d];
 58     p->pushdown();
 59     int d1=p->cmp(k);
 60     int k1=(d1)?k-p->ch[0]->s-1:k;
 61     if(d1!=-1){
 62         splay(p->ch[d1],k1); 
 63         d==d1?rot(o,d^1):rot(o->ch[d],d); 
 64     }
 65     rot(o,d^1);
 66 }
 67 struct queue{
 68     int fron,rear,cnt;
 69     node*x[maxn<<1];
 70     queue(){
 71         fron=0;rear=0;
 72     }
 73     inline void push(node*o){
 74         x[rear++]=o;
 75     }
 76     inline node*front(){
 77         return x[fron];
 78     }
 79     inline void pop(){
 80         fron++;
 81     }
 82 };
 83 queue Q;
 84 node*newnode(char ch){
 85     node*o=Q.front();Q.pop();
 86     o->ch[0]=o->ch[1]=null;
 87     o->s=1;o->rev=0;
 88     o->c=ch;
 89     return o;
 90 }
 91 node*build(int l,int r){
 92     if(l>=r) return null;
 93     int mid=(l+r)>>1;
 94     node*o=newnode(a[mid]);
 95     if(l<mid) o->ch[0]=build(l,mid);
 96     if(r>mid+1) o->ch[1]=build(mid+1,r);
 97     o->maintain();
 98     return o;
 99 }
100 node x[maxn];
101 void init(){
102     a[1]=‘$‘;a[2]=‘$‘;
103     rep(i,0,maxn) Q.push(x+i);
104     null=newnode(0);
105     null->s=0;
106     root=build(1,3);
107 }
108 #define ok(c) (c>=32&&c<=126)
109 void read(int l){
110     int cnt=0;
111     char ch=getchar();
112     while(!ok(ch)) ch=getchar();
113     while(cnt<l){
114         a[++cnt]=ch;//cout<<ch;
115         ch=0;
116         while(!ok(ch)&&cnt<l) ch=getchar();
117     }
118     //cout<<endl;
119 }
120 void del(node*o){
121     if(o==null) return;
122     del(o->ch[0]);
123     Q.push(o);
124     del(o->ch[1]);
125 }
126 void dfs(node*o){
127     if(o==null) return;
128     o->pushdown();
129     dfs(o->ch[0]);
130     putchar(o->c);
131     dfs(o->ch[1]);
132 }
133 int main(){
134     //freopen("test.in","r",stdin);
135     //freopen("test.out","w",stdout);
136     scanf("%d",&n);
137     init();
138     while(n--){
139     //    dfs(root);
140     //    putchar(‘\n‘);
141         int len;
142         char opt[20];
143         scanf(" %s",opt);
144         if(opt[0]==‘M‘) scanf("%d",&now);
145         else if(opt[0]==‘I‘){
146             scanf("%d",&len);read(len);
147             splay(root,now+1);splay(root->ch[1],now-root->ch[0]->s+1);
148             root->ch[1]->ch[0]=build(1,len+1);
149             root->maintain();root->ch[1]->maintain();
150         }else if(opt[0]==‘D‘){
151             scanf("%d",&len);
152             splay(root,now+1);splay(root->ch[1],now-root->ch[0]->s+len+1);
153             del(root->ch[1]->ch[0]);root->ch[1]->ch[0]=null;
154             root->maintain();root->ch[1]->maintain();
155         }else if(opt[0]==‘R‘){
156             scanf("%d",&len);
157             splay(root,now+1);splay(root->ch[1],now-root->ch[0]->s+len+1);
158             root->ch[1]->ch[0]->Rev();
159         }else if(opt[0]==‘G‘){
160             splay(root,now+2);
161             putchar(root->c);putchar(‘\n‘);
162             //putchar(root->c);
163         }else if(opt[0]==‘P‘) now--;
164         else if(opt[0]==‘N‘) now++;
165         //cout<<opt<<" ok\n";
166     }
167     //fclose(stdin);
168     //fclose(stdout);
169     return 0;
170 }