[BZOJ3224]普通平衡树

模板题嘛。。

splay：

#include<iostream>#include<cstdio>#include<memory.h>#define maxn 500005using namespace std;int i,n,opt,x,nd=0,ans,root=0,c[maxn][2],size[maxn],pre[maxn],same[maxn],num[maxn];void update(int x){size[x]=size[c[x][0]]+size[c[x][1]]+same[x];}void newnode(int &x,int fa,int k){x=++nd;pre[x]=fa;size[x]=same[x]=1;c[x][0]=c[x][1]=0;num[x]=k;}void rot(int x,int kind){int y=pre[x],z=pre[y];c[y][!kind]=c[x][kind];pre[c[x][kind]]=y;c[x][kind]=y;pre[y]=x;pre[x]=z;if (z) c[z][c[z][1]==y]=x;update(y);update(x);}void splay(int x,int goal){int kind,y,z;while (pre[x]!=goal){y=pre[x];if (pre[y]==goal) rot(x,c[y][0]==x);else{z=pre[y];kind=c[z][0]==y;if (c[y][kind]==x) rot(x,!kind);else rot(y,kind);rot(x,kind);}}if (goal==0) root=x;}void ins(int k){int get=root;if (!root) newnode(root,0,k);if (num[get]==k){same[get]++;size[get]++;return;}while (c[get][num[get]<k]){get=c[get][num[get]<k];if (num[get]==k){same[get]++;size[get]++;splay(get,0);return;}}newnode(c[get][num[get]<k],get,k);splay(c[get][num[get]<k],0);}void find(int x,int k){if (num[x]==k) {splay(x,0);return;}else find(c[x][num[x]<k],k);}int join(int s1,int s2){while (c[s1][1]) s1=c[s1][1];splay(s1,pre[s2]);c[s1][1]=s2;pre[s2]=s1;update(s1);return s1;}void del(int k){find(root,k);if (c[root][0]*c[root][1]==0) {root=c[root][0]+c[root][1];return;}root=join(c[root][0],c[root][1]);}int rank(int x,int k){if (num[x]==k) return size[c[x][0]]+1;if (num[x]>k) return rank(c[x][0],k);else return rank(c[x][1],k)+size[c[x][0]]+same[x];}int findkth(int x,int k){if (size[c[x][0]]>=k) return findkth(c[x][0],k);if (size[c[x][0]]+same[x]>=k) return num[x];return findkth(c[x][1],k-size[c[x][0]]-same[x]);}void getpre(int x,int k){if (!x) return;if (num[x]<k){ans=x;getpre(c[x][1],k);}else getpre(c[x][0],k);}void getpos(int x,int k){if (!x) return;if (num[x]>k){ans=x;getpre(c[x][0],k);}else getpre(c[x][1],k);}int main(){scanf("%d",&n);for (i=1;i<=n;i++){scanf("%d%d",&opt,&x);switch(opt){case 1:ins(x);break;case 2:del(x);break;case 3:printf("%d\n",rank(root,x));break;case 4:printf("%d\n",findkth(root,x));break;case 5:getpre(root,x);printf("%d\n",num[ans]);break;case 6:getpos(root,x);printf("%d\n",num[ans]);break;}}}

treap：

#include<iostream>#include<cstdio>#include<memory.h>#include<cstdlib>#include<time.h>#define maxn 500005using namespace std;int i,n,opt,x,nd=0,ans,root=0,c[maxn][2],size[maxn],same[maxn],fix[maxn],num[maxn];void update(int x){size[x]=size[c[x][0]]+size[c[x][1]]+same[x];}void newnode(int &x,int k){x=++nd;c[x][0]=c[x][1]=0;size[x]=same[x]=1;fix[x]=rand();num[x]=k;}void rot(int &x,int kind){int t=c[x][!kind];c[x][!kind]=c[t][kind];c[t][kind]=x;update(x);update(t);x=t;}void ins(int &x,int k){if (!x) {newnode(x,k);return;}size[x]++;if (num[x]==k) {same[x]++;return;}ins(c[x][num[x]<k],k);if (fix[c[x][num[x]<k]]<fix[x]) rot(x,!(num[x]<k));}void del(int &x,int k){if (num[x]==k){if (same[x]>1) {size[x]--,same[x]--;return;}if (c[x][0]*c[x][1]==0) {x=c[x][0]+c[x][1];return;}rot(x,fix[c[x][0]]<fix[c[x][1]]);del(x,k);}else size[x]--,del(c[x][num[x]<k],k);}int rank(int x,int k){if (num[x]==k) return size[c[x][0]]+1;if (num[x]>k) return rank(c[x][0],k);else return rank(c[x][1],k)+size[c[x][0]]+same[x];}int findkth(int x,int k){if (size[c[x][0]]>=k) return findkth(c[x][0],k);if (size[c[x][0]]+same[x]>=k) return num[x];return findkth(c[x][1],k-size[c[x][0]]-same[x]);}void getpre(int x,int k){if (!x) return;if (num[x]<k) {ans=x;getpre(c[x][1],k);} else getpre(c[x][0],k);}void getpos(int x,int k){if (!x) return;if (num[x]>k) {ans=x;getpos(c[x][0],k);} else getpos(c[x][1],k);}int main() {srand((unsigned)time(0));scanf("%d",&n);for (i=1;i<=n;i++){scanf("%d%d",&opt,&x);switch(opt){case 1:ins(root,x);break;case 2:del(root,x);break;case 3:printf("%d\n",rank(root,x));break;case 4:printf("%d\n",findkth(root,x));break;case 5:getpre(root,x);printf("%d\n",num[ans]);break;case 6:getpos(root,x);printf("%d\n",num[ans]);break;}}}