UVA-12538:Version Controlled IDE

Description

---

使用可持久化的FHQ_Treap，维护各版本，注意一些题目里的细节就好。

#include<ctime>
#include<stack>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
using namespace std;

const int MAXN = 1000000+9;
int lastans;
int n;
struct PAIR{
	int left,right;
	PAIR(int _x=0,int _y=0):left(_x),right(_y){}
};
struct T{
	int ls,rs;
	char val;
	int size;
	int RD;
}tree[MAXN*22];
int rt[MAXN];
int cnt;
char BUF[MAXN];
int Verson;

int New_Node(char val=0){
	int now=++cnt;
	tree[now].val=val;
	tree[now].size=1;
	tree[now].RD=rand();
	return now;
}

int Copy_Node(int x){
	int now=New_Node();
	tree[now]=tree[x];
	return now;
}

void Clean(T &A){
	A.ls=A.rs=A.val=A.size=A.RD=0;
}

void update(int x){
	tree[x].size=tree[tree[x].ls].size+tree[tree[x].rs].size+1;
}

int Build(char *S,int &len){
	static stack<int> sta;
	while(!sta.empty())sta.pop();
	len=strlen(S);
	int from=cnt+1;
	for(int i=0;i<len;i++){
		int now=++cnt;
		tree[now].RD=rand();
		tree[now].val=S[i];
		tree[now].size=1;
	}
	int to=cnt;
	sta.push(0);
	Clean(tree[0]);
	int top;
	for(int i=from;i<=to;i++){
		while(true){
			top=sta.top();
			if(tree[top].RD<=tree[i].RD)
				break;
			update(top);
			sta.pop();
		}
		tree[i].ls=tree[top].rs;
		tree[top].rs=i;
		sta.push(i);
	}
	while(sta.size()>1){
		update(sta.top());
		sta.pop();
	}
	return tree[0].rs;
}

PAIR split(int k,int val){
	PAIR re;
	if(!k)return re;
	int now=Copy_Node(k);
	if(tree[tree[k].ls].size+1<=val){
		re=split(tree[k].rs,val-(tree[tree[k].ls].size+1));
		tree[now].rs=re.left;
		re.left=now;
	}
	else{
		re=split(tree[k].ls,val);
		tree[now].ls=re.right;
		re.right=now;
	}
	update(now);
	return re;
}

int merge(int x,int y){
	if(x==0 || y==0)
		return x+y;
	if(tree[x].RD<tree[y].RD){
		tree[x].rs=merge(tree[x].rs,y);
		update(x);
		return x;
	}
	else{
		tree[y].ls=merge(x,tree[y].ls);
		update(y);
		return y;
	}
}

void insert(int pre,int now,int loc){
	int len;
	int tmp=Build(BUF,len);
	PAIR rt1=split(rt[pre],loc);
	rt[now]=merge(rt1.left,merge(tmp,rt1.right));
}

void del(int pre,int now,int loc,int len){
	PAIR rt1=split(rt[pre],loc-1);
	PAIR rt2=split(rt1.right,len);
	rt[now]=merge(rt1.left,rt2.right);
}

void InOrder(int k){
	if(!k)return;
	InOrder(tree[k].ls);
	putchar(tree[k].val);
	if(tree[k].val=='c')lastans++;
	InOrder(tree[k].rs);
}

void OUTPUT(int pre,int loc,int len){
	PAIR rt1=split(rt[pre],loc-1);
	PAIR rt2=split(rt1.right,len);
	InOrder(rt2.left);
	puts("");
	rt[pre]=merge(rt1.left,merge(rt2.left,rt2.right));
}

int main(){
	srand(time(0));
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		int opt,loc,len,v;
		scanf("%d",&opt);
		switch(opt){
			case 1:scanf("%d",&loc);scanf("%s",BUF);
			       loc-=lastans;
			       Verson++;
			       insert(Verson-1,Verson,loc);
			       break;
			case 2:
			       scanf("%d%d",&loc,&len);
			       loc-=lastans;len-=lastans;
			       Verson++;
			       del(Verson-1,Verson,loc,len);
			       break;
			default:
			       scanf("%d%d%d",&v,&loc,&len);
			       v-=lastans;loc-=lastans;len-=lastans;
			       OUTPUT(v,loc,len);
		}
	}
	return 0;
}