splay
随便敲敲练手。。。
1 #include<bits/stdc++.h> 2 using namespace std; 3 typedef long long LL; 4 const int inf=1e9; 5 const int maxn=200000; 6 int N,M,T,tot,root; 7 int key[maxn],lc[maxn],rc[maxn],fa[maxn],siz[maxn]; 8 inline void update(int x){ 9 siz[x]=siz[lc[x]]+siz[rc[x]]+1; 10 } 11 inline void r_rotate(int x){ 12 int y=fa[x]; 13 lc[y]=rc[x]; 14 if(rc[x]) fa[rc[x]]=y; 15 fa[x]=fa[y]; 16 if(y==lc[fa[y]]) lc[fa[y]]=x; 17 else rc[fa[y]]=x; 18 fa[y]=x; rc[x]=y; 19 update(y); update(x); 20 } 21 inline void l_rotate(int x){ 22 int y=fa[x]; 23 rc[y]=lc[x]; 24 if(lc[x]) fa[lc[x]]=y; 25 fa[x]=fa[y]; 26 if(y==lc[fa[y]]) lc[fa[y]]=x; 27 else rc[fa[y]]=x; 28 fa[y]=x; lc[x]=y; 29 update(y); update(x); 30 } 31 inline void splay(int x,int s){ 32 int p; 33 while(fa[x]!=s){ 34 int p=fa[x]; 35 if(fa[p]==s){ 36 if(x==lc[p]) r_rotate(x); 37 else l_rotate(x); 38 break; 39 } 40 else if(x==lc[p]){ 41 if(p==lc[fa[p]]) r_rotate(x),r_rotate(x); 42 else r_rotate(x),l_rotate(x); 43 } 44 else if(x==rc[p]){ 45 if(p==rc[fa[p]]) l_rotate(x),l_rotate(x); 46 else l_rotate(x),r_rotate(x); 47 } 48 } 49 if(s==0) root=x; 50 } 51 52 inline void insert(int v){ 53 if(root==0){ 54 root=++tot; 55 rc[0]=tot; key[root]=v; siz[root]=1; 56 return ; 57 } 58 int tmp,x=root; 59 while(x!=0){ 60 tmp=x; 61 if(v<=key[x]) siz[x]++,x=lc[x]; 62 else siz[x]++,x=rc[x]; 63 } 64 if(v<=key[tmp]){ 65 lc[tmp]=++tot; 66 fa[tot]=tmp; key[tot]=v; siz[tot]=1; 67 } 68 else{ 69 rc[tmp]=++tot; 70 fa[tot]=tmp; key[tot]=v; siz[tot]=1; 71 } 72 splay(tot,0); 73 } 74 75 inline int find(int v){ 76 int x=root; 77 while(x!=0){ 78 if(v<key[x]) x=lc[x]; 79 else if(v>key[x]) x=rc[x]; 80 else{ 81 splay(x,0); 82 return x; 83 } 84 } 85 return -1; 86 } 87 88 inline int getmax(int x){ 89 int tmp; 90 while(x!=0){ 91 tmp=x; x=rc[x]; 92 } 93 return tmp; 94 } 95 inline int getmin(int x){ 96 int tmp; 97 while(x!=0){ 98 tmp=x; x=lc[x]; 99 } 100 return tmp; 101 } 102 103 inline void Delete(int v){ 104 int x=find(v); 105 if(x==-1) return ; 106 int pp=getmax(lc[x]),nn=getmin(rc[x]); 107 if(lc[x]==0||rc[x]==0){ 108 if(lc[x]==0&&rc[x]==0){ 109 root=0; rc[0]=0; 110 return ; 111 } 112 else if(lc[x]==0){ 113 rc[0]=rc[x]; fa[rc[x]]=0; root=rc[x]; rc[x]=0; 114 siz[x]=1; 115 return ; 116 } 117 else{ 118 rc[0]=lc[x]; fa[lc[x]]=0; root=lc[x]; lc[x]=0; 119 siz[x]=1; 120 return ; 121 } 122 } 123 splay(pp,0); splay(nn,root); 124 fa[lc[nn]]=0; siz[lc[nn]]=1; lc[nn]=0; 125 update(nn); update(pp); 126 } 127 128 inline int rank(int x,int v){ 129 if(x==0) return 1; 130 if(v<=key[x]) return rank(lc[x],v); 131 else return siz[lc[x]]+1+rank(rc[x],v); 132 } 133 inline int findkth(int x,int k){ 134 if(siz[lc[x]]+1==k) return key[x]; 135 if(siz[lc[x]]+1>k) return findkth(lc[x],k); 136 return findkth(rc[x],k-siz[lc[x]]-1); 137 } 138 inline int pred(int rt,int v){ 139 if(rt==0) return v; 140 if(v<=key[rt]) return pred(lc[rt],v); 141 else{ 142 int ans=pred(rc[rt],v); 143 if(ans==v) return key[rt]; 144 return ans; 145 } 146 } 147 inline int succ(int rt,int v){ 148 if(rt==0) return v; 149 if(v>=key[rt]) return succ(rc[rt],v); 150 else{ 151 int ans=succ(lc[rt],v); 152 if(ans==v) return key[rt]; 153 return ans; 154 } 155 } 156 157 int main(){ 158 freopen("3224.in","r",stdin); 159 freopen("3224.out","w",stdout); 160 scanf("%d",&T); 161 while (T--){ 162 int kin,num; 163 scanf("%d%d",&kin,&num); 164 if(kin==1) insert(num); 165 else if(kin==2) Delete(num); 166 else if(kin==3) printf("%d\n",rank(root,num)); 167 else if(kin==4) printf("%d\n",findkth(root,num)); 168 else if(kin==5) printf("%d\n",pred(root,num)); 169 else if(kin==6) printf("%d\n",succ(root,num)); 170 } 171 return 0; 172 }
