1 #include<cstdio> 2 #include<cstring> 3 #include<iostream> 4 #include<algorithm> 5 #include<vector> 6 using namespace std; 7 struct NODE{ 8 NODE *ls,*rs; 9 int r,s,v; 10 int rev; 11 #define size(x) ((x)?(x)->s:0) 12 NODE(int v=0):v(v){ 13 r=rand(); 14 ls=rs=NULL; 15 s=1; 16 rev=0; 17 } 18 void reverse(){ 19 if(!this) return; 20 swap(ls,rs); 21 rev^=1; 22 } 23 void pushdown(){ 24 if(!this) return; 25 if(rev){ 26 ls->reverse(); 27 rs->reverse(); 28 rev^=1; 29 } 30 } 31 void mt(){ 32 s=1+size(ls)+size(rs); 33 } 34 }; 35 36 typedef NODE *pnode; 37 typedef pair<NODE*,NODE*>droot; 38 NODE *merge(NODE *a,NODE *b){//treap为了满足中序序列，左右子树不能交换 39 if(!a) return b; 40 if(!b) return a; 41 if(a->r < b->r){//小根堆 42 a->pushdown(); 43 a->rs=merge(a->rs,b); 44 a->mt(); 45 return a; 46 } 47 else { 48 b->pushdown(); 49 b->ls=merge(a,b->ls); 50 b->mt(); 51 return b; 52 } 53 } 54 droot split(NODE *x,int k){ 55 if(!x) return droot(NULL,NULL); 56 x->pushdown(); 57 droot r; 58 if(size(x->ls) >= k){ 59 r=split(x->ls,k); 60 x->ls=r.second; 61 x->mt(); 62 r.second=x; 63 } 64 else { 65 r=split(x->rs,k-size(x->ls)-1); 66 x->rs=r.first; 67 x->mt(); 68 r.first=x; 69 } 70 return r; 71 } 72 //名次树用的普通写法 73 int kth(NODE *x,int k){// 74 if(!x || k<=0 || k>size(x)) return 0; 75 int s=size(x->rs); 76 if(k == s+1) return x->v; 77 else if(k <= s) return kth(x->ls,k); 78 else return kth(x->rs,k-size(x->ls)-1); 79 } 80 int rank(NODE *x,int v){ 81 if(!x) return 0; 82 if(v < x->v) return rank(x->ls,v); 83 else return rank(x->rs,v)+size(x->ls)+1; 84 } 85 NODE *insert(NODE *root,int v){ 86 int k=rank(root,v); 87 droot x=split(root,k); 88 NODE *o=new NODE(v); 89 return merge(merge(x.first,o),x.second); 90 } 91 NODE *build(int *a,int n){ 92 pnode *stk=new pnode[n]; 93 NODE *last; 94 int tp=0; 95 for(int i=1;i<=n;i++){ 96 NODE *p=new NODE(i); 97 last=NULL; 98 while(tp && stk[tp-1]->r > p->r){ 99 stk[tp-1]->mt(); 100 last=stk[tp-1]; 101 stk[--tp]=NULL; 102 } 103 if(tp) stk[tp-1]->rs=p; 104 p->ls=last; 105 stk[tp++]=p; 106 } 107 while(tp) stk[--tp]->mt(); 108 NODE *r=stk[0]; 109 delete []stk; 110 return r; 111 } 112 113 void dfs(NODE *u){ 114 if(!u) return; 115 u->pushdown(); 116 dfs(u->ls); 117 printf("%d ",u->v); 118 dfs(u->rs); 119 } 120 121 int n,m; 122 int d[100010]; 123 int main(){ 124 freopen("sph.in", "r", stdin); 125 freopen("sph.out", "w", stdout); 126 scanf("%d %d",&n,&m); 127 NODE *t=build(d,n); 128 while(m--){ 129 int l,r; 130 scanf("%d %d",&l,&r); 131 droot p1=split(t,l-1); 132 droot p2=split(p1.second,r-l+1); 133 p2.first->reverse(); 134 t=merge(p1.first,merge(p2.first,p2.second)); 135 } 136 dfs(t); 137 return(0); 138 }