UVA - 12538 Version Controlled IDE (可持久化treap)

紫薯例题

 #include<bits/stdc++.h>
 using namespace std;
 typedef long long ll;
 const int N=1e6+,inf=0x3f3f3f3f;
 int rt[N],siz[N*],ch[N*][],tot,n,d,ver;
 char buf[N],val[N*];
 #define l(u) ch[u][0]
 #define r(u) ch[u][1]
 int rnd() {
     const int M=(1ll<<)-,X=;
     static int seed=time()%M;
     return seed=(ll)seed*X%M;
 }
 int newnode(char c) {int u=++tot; siz[u]=,l(u)=r(u)=,val[u]=c; return u;}
 int cpy(int v) {int u=++tot; siz[u]=siz[v],l(u)=l(v),r(u)=r(v),val[u]=val[v]; return u;}
 void pu(int u) {siz[u]=siz[l(u)]+siz[r(u)]+;}
 void sp(int w,int k,int& u,int& v) {
     if(!w) {u=v=; return;}
     if(k<=siz[l(w)])v=cpy(w),sp(l(w),k,u,l(v)),pu(v);
     else u=cpy(w),sp(r(w),k-(siz[l(w)]+),r(u),v),pu(u);
 }
 void mg(int& w,int u,int v) {
     if(!u||!v) {w=u|v; return;}
     if(rnd()%(siz[u]+siz[v])<siz[u])w=u,mg(r(w),r(u),v);
     else w=v,mg(l(w),u,l(v));
     pu(w);
 }
 void build(int& u,int l,int r) {
     if(l>r) {u=; return;}
     int mid=(l+r)>>;
     u=newnode(buf[mid]);
     build(l(u),l,mid-),build(r(u),mid+,r),pu(u);
 }
 void ins(int& rt,int p) {
     int n=strlen(buf);
     int L,M,R;
     build(M,,n-);
     sp(rt,p,L,R),mg(L,L,M),mg(rt,L,R);
 }
 void del(int& rt,int p,int c) {
     int L,M,R;
     sp(rt,p+c-,L,R),sp(L,p-,L,M),mg(rt,L,R);
 }
 void dfs(int u) {
     if(!u)return;
     dfs(l(u)),putchar(val[u]),dfs(r(u));
     if(val[u]=='c')++d;
 }
 void pr(int& rt,int p,int c) {
     int L,M,R;
     sp(rt,p+c-,L,R),sp(L,p-,L,M);
     dfs(M),puts("");
     mg(L,L,M),mg(rt,L,R);
 }
 int main() {
     scanf("%d",&n);
     for(int i=; i<=n; ++i) {
         int f;
         scanf("%d",&f);
         if(f==) {
             int p;
             scanf("%d%s",&p,buf),p-=d;
             ++ver,ins(rt[ver]=rt[ver-],p);
         } else if(f==) {
             int p,c;
             scanf("%d%d",&p,&c),p-=d,c-=d;
             ++ver,del(rt[ver]=rt[ver-],p,c);
         } else {
             int v,p,c;
             scanf("%d%d%d",&v,&p,&c),v-=d,p-=d,c-=d;
             pr(rt[v],p,c);
         }
     }
     return ;
 }