[NOI2003]文本编辑器 [Fhq Treap]

[NOI2003]文本编辑器

没啥好说的 就是个板子

#include <bits/stdc++.h>
// #define int long long
#define rep(a , b , c) for(int a = b ; a <= c ; ++ a)
#define Rep(a , b , c) for(int a = b ; a >= c ; -- a)
#define go(u) for(int i = G.head[u] , v = G.to[i] , w = G.dis[i] ; i ; v = G.to[i = G.nxt[i]] , w = G.dis[i])

using namespace std ;
using ll = long long ;
using pii = pair < int , int > ;
using vi = vector < int > ;

int read() {
  int x = 0 ; bool f = 1 ; char c = getchar() ;
  while(c < 48 || c > 57) { if(c == '-') f = 0 ; c = getchar() ; }
  while(c > 47 && c < 58) { x = (x << 1) + (x << 3) + (c & 15) ; c = getchar() ; }
  return f ? x : -x ;
}

template <class T> void print(T x , char c = '\n') {
  static char st[100] ; int stp = 0 ;
  if(! x) { putchar('0') ; }
  if(x < 0) { x = -x ; putchar('-') ; }
  while(x) { st[++ stp] = x % 10 ^ 48 ; x /= 10 ; }
  while(stp) { putchar(st[stp --]) ; } putchar(c) ;
}

template <class T> void cmax(T & x , T y) { x < y ? x = y : 0 ; }
template <class T> void cmin(T & x , T y) { x > y ? x = y : 0 ; }

const int _N = 1e6 + 10 ;
struct Group {
  int head[_N] , nxt[_N << 1] , to[_N] , dis[_N] , cnt = 1 ;
  Group () { memset(head , 0 , sizeof(head)) ; }
  void add(int u , int v , int w = 1) { nxt[++ cnt] = head[u] ; to[cnt] = v ; dis[cnt] = w ; head[u] = cnt ; }
} ;

const int N = 1e7 + 10  ;
typedef int arr[N] ;
int GB ;
int rt = 0 , cnt = 0 ;
char val[N] ;
int sz[N] , rnd[N] ;
int ch[N][2] ;
#define ls(x) ch[x][0]
#define rs(x) ch[x][1]
int NewNode(char c) {
	val[++ cnt] = c ;
	sz[cnt] = 1 ;
	rnd[cnt] = rand() ;
	return cnt ;
}
void pushup(int x) {
	sz[x] = sz[ls(x)] + sz[rs(x)] + 1 ;
}
int merge(int x , int y) {
	if(! x || ! y) return x | y ;
	if(rnd[x] < rnd[y]) {
		rs(x) = merge(rs(x) , y) ;
		pushup(x) ;
		return x ;
	}
	else {
		ls(y) = merge(x , ls(y)) ;
		pushup(y) ;
		return y ;
	}
}
void split(int cur , int k , int & x , int & y) {
	if(! cur) {
		x = y = 0 ;
		return ;
	}
	if(sz[ls(cur)] < k) {
		x = cur ;
		split(rs(x) , k - sz[ls(x)] - 1 , rs(x) , y) ;
		pushup(x) ;
		return ;
	}
	else {
		y = cur ;
		split(ls(y) , k , x , ls(y)) ;
		pushup(y) ;
		return ;
	}
}
void Move(int x) {
	GB = x ;
}
void Insert(int len) {
	int x , y ;
	split(rt , GB , x , y) ;
	int _cnt = 0 ; char c = getchar() ;
	int Newroot = 0 ;
	while(_cnt < len) {
		if(c >= 32 && c <= 126 && c != '\n') ++ _cnt , Newroot = merge(Newroot , NewNode(c)) ;
		c = getchar() ;
	}
	rt = merge(x , merge(Newroot , y)) ;
}
void Delete(int len) {
	int x , y , z ;
	split(rt , GB , x , y) ;
	split(y , len , y , z) ;
	rt = merge(x , z) ;
}
void dfs(int o) {
	if(ls(o)) dfs(ls(o)) ;
	putchar(val[o]) ;
	if(rs(o)) dfs(rs(o)) ;
}
void Get(int len) {
	int x , y , z ;
	split(rt , GB , x , y) ;
	split(y , len , y , z) ;
	dfs(y) ; putchar('\n') ;
	rt = merge(merge(x , y) , z) ;
}
void Prev() {
	-- GB ;
}
void Next() {
	++ GB ;
}
string s ;
signed main() {
	int q = read() ;
	while(q --) {
		cin >> s ;
		if(s == "Move") Move(read()) ;
		if(s == "Insert") Insert(read()) ;
		if(s == "Delete") Delete(read()) ;
		if(s == "Get") Get(read()) ;
		if(s == "Prev") Prev() ;
		if(s == "Next") Next() ;
	}
	return 0 ;
}