还没写过splay树上的lazy标记。写得还算顺利，不过自己出数据错了浪费了好多时间QAQ
在debug过程中深刻体会到了gdb的好处orz
1 #include<bits/stdc++.h> 2 #define inc(i,l,r) for(i=l;i<=r;i++) 3 #define dec(i,l,r) for(i=l;i>=r;i--) 4 #define mem(a) memset(a,0,sizeof(a)) 5 #define NM 100000+10 6 #define inf 1e9 7 using namespace std; 8 int n,m,i,x,y; 9 struct splautree{ 10 int root,c[NM][2],f[NM],a[NM],tot,z[NM],b[NM]; 11 void newnode(int &r,int k,int fa){ 12 a[r=++tot]=k;f[r]=fa;c[r][0]=c[r][1]=0; 13 } 14 void rot(int x,int kind){ 15 int y=f[x]; 16 c[y][!kind]=c[x][kind]; 17 f[c[x][kind]]=y; 18 c[x][kind]=y; 19 f[x]=f[y]; 20 if(f[x])c[f[y]][c[f[y]][1]==y]=x; 21 f[y]=x; 22 b[y]=b[c[y][0]]+b[c[y][1]]+1; 23 b[x]=b[c[x][0]]+b[c[x][1]]+1; 24 } 25 void splay(int x,int goal){ 26 while(f[x]!=goal){ 27 if(f[f[x]]==goal)rot(x,c[f[x]][0]==x); 28 else{ 29 int y=f[x],kind=c[f[y]][0]==y; 30 if(c[y][kind]==x){ 31 rot(x,!kind); 32 rot(x,kind); 33 }else{ 34 rot(y,kind); 35 rot(x,kind); 36 } 37 } 38 } 39 if(goal==0)root=x; 40 } 41 void build(){ 42 int i; 43 newnode(root,0,0);b[1]=n+2; 44 int r=root; 45 inc(i,1,n){ 46 newnode(c[r][1],i,r); 47 r=c[r][1]; 48 b[r]=n+2-i; 49 } 50 newnode(c[r][1],0,r);r=c[r][1];b[r]=1; 51 } 52 void pushdown(int x){ 53 if(z[x]%2){ 54 swap(c[x][1],c[x][0]); 55 z[c[x][1]]^=1;z[c[x][0]]^=1; 56 z[x]=0; 57 } 58 } 59 int find(int x){ 60 int r=root;x++; 61 while(x>0){ 62 pushdown(r); 63 if(x==b[c[r][0]]+1)return r; 64 else 65 if(x>b[c[r][0]]+1){ 66 x-=b[c[r][0]]+1; 67 r=c[r][1]; 68 }else r=c[r][0]; 69 } 70 } 71 void flip(int x,int y){ 72 int t; 73 t=find(x-1); 74 splay(t,0); 75 int v=find(y+1); 76 splay(v,t); 77 t=c[v][0]; 78 z[t]^=1; 79 pushdown(t); 80 } 81 void output(int x){ 82 pushdown(x); 83 if(c[x][0])output(c[x][0]); 84 if(a[x])printf("%d ",a[x]); 85 if(c[x][1])output(c[x][1]); 86 } 87 }tree; 88 int main(){ 89 scanf("%d%d",&n,&m); 90 tree.build(); 91 inc(i,1,m){ 92 scanf("%d%d",&x,&y); 93 tree.flip(x,y); 94 } 95 tree.output(tree.root); 96 return 0; 97 }