平衡树系列第二题
轩神的split还是这么好写%%%
还是要注意虚拟结点
1 #include<algorithm> 2 #include<iostream> 3 #include<cstdlib> 4 #include<cstring> 5 #include<cstdio> 6 #include<string> 7 #include<cmath> 8 #include<ctime> 9 #include<queue> 10 #include<stack> 11 #include<map> 12 #include<set> 13 #define rre(i,r,l) for(int i=(r);i>=(l);i--) 14 #define re(i,l,r) for(int i=(l);i<=(r);i++) 15 #define Clear(a,b) memset(a,b,sizeof(a)) 16 #define inout(x) printf("%d",(x)) 17 #define douin(x) scanf("%lf",&x) 18 #define strin(x) scanf("%s",(x)) 19 #define LLin(x) scanf("%lld",&x) 20 #define op operator 21 #define CSC main 22 typedef unsigned long long ULL; 23 typedef const int cint; 24 typedef long long LL; 25 using namespace std; 26 void inin(int &ret) 27 { 28 ret=0;int f=0;char ch=getchar(); 29 while(ch<'0'||ch>'9'){if(ch=='-')f=1;ch=getchar();} 30 while(ch>='0'&&ch<='9')ret*=10,ret+=ch-'0',ch=getchar(); 31 ret=f?-ret:ret; 32 } 33 int ch[100010][2],w[100010],s[100010],rev[100010],fa[100010],ed,root; 34 void maintain(int k){s[k]=s[ch[k][0]]+s[ch[k][1]]+1;} 35 int newnode(int v,int f) 36 { 37 ed++; 38 w[ed]=v,fa[ed]=f; 39 ch[ed][0]=ch[ed][1]=0; 40 s[ed]=1;rev[ed]=0; 41 return ed; 42 } 43 void down(int k) 44 { 45 if(rev[k]) 46 { 47 swap(ch[k][0],ch[k][1]); 48 rev[ch[k][0]]^=1,rev[ch[k][1]]^=1; 49 rev[k]=0; 50 } 51 } 52 void rotate(int x) 53 { 54 int y=fa[x],z=fa[y]; 55 if(z)ch[z][ch[z][1]==y]=x; 56 int l=ch[y][1]==x,r=l^1; 57 fa[y]=x,fa[x]=z; 58 if(ch[x][r])fa[ch[x][r]]=y; 59 ch[y][l]=ch[x][r],ch[x][r]=y; 60 maintain(y); 61 } 62 int sta[100010],top; 63 void splay(int k,int f) 64 { 65 top=0; 66 for(int i=k;i!=f;i=fa[i])sta[++top]=i; 67 while(top)down(sta[top--]); 68 while(fa[k]!=f) 69 { 70 int y=fa[k],z=fa[y]; 71 if(z!=f) 72 if((ch[z][1]==y)^(ch[y][1]==k))rotate(k); 73 else rotate(y);else ; 74 rotate(k); 75 } 76 maintain(k); 77 if(!f)root=k; 78 } 79 int tot,a[100010]; 80 int kth(int k) 81 { 82 int x=root; 83 while(x) 84 { 85 down(x); 86 int pp=s[ch[x][0]]+1; 87 if(pp==k)return x; 88 if(pp<k)k-=pp,x=ch[x][1]; 89 else x=ch[x][0]; 90 }return 0; 91 } 92 int build(int f,int l,int r) 93 { 94 if(l>r)return 0; 95 int mid=(l+r)>>1; 96 int k=newnode(a[mid],f); 97 ch[k][0]=build(k,l,mid-1); 98 ch[k][1]=build(k,mid+1,r); 99 maintain(k);return k; 100 } 101 int split(int l,int r) 102 { 103 int x=kth(l),y=kth(r+2); 104 splay(x,0);splay(y,x); 105 return ch[y][0]; 106 } 107 int n,m; 108 void print(int k) 109 { 110 if(!k)return ; 111 down(k); 112 print(ch[k][0]); 113 printf("%d ",w[k]); 114 print(ch[k][1]); 115 } 116 int CSC() 117 { 118 inin(n),inin(m); 119 re(i,1,n+2)a[i]=i-1; 120 root=build(0,1,n+2); 121 re(i,1,m) 122 { 123 int L,R; 124 inin(L),inin(R); 125 int hh=split(L,R); 126 rev[hh]^=1; 127 } 128 int hh=split(1,n); 129 print(hh); 130 return 0; 131 }