非指针版
1 #define lo ch[o][0] 2 #define ro ch[o][1] 3 void maintain(int o){sz[o]=1+sz[lo]+sz[ro];} 4 void pushdown(int o){if(!laz[o]) return ; swap(lo, ro); if(lo) laz[lo]^=1; if(ro) laz[ro]^=1; laz[o]=0;} 5 void ins(int &o, int x){ 6 if(!o){o=++cnt; val[o]=x; sz[o]=1; return ;} 7 if(x < val[o]) ins(ch[o][0], x); else ins(ch[o][1], x); maintain(o); 8 } 9 void rot(int &o, int d){ 10 pushdown(o); int p=ch[o][d^1]; pushdown(p); 11 ch[o][d^1]=ch[p][d]; ch[p][d]=o; maintain(o); maintain(p); o=p; 12 } 13 int scmp(int o, int &k){if(sz[lo]+1 == k) return -1; if(sz[lo]+1 > k) return 0; k-=sz[lo]+1; return 1;} 14 void splay(int &o, int k){ 15 if(!o) return ; pushdown(o); int d=scmp(o, k); if(d == -1) return ; 16 int p=ch[o][d]; if(!p) return ; pushdown(p); 17 int k2=k, d2=scmp(p, k2); if(d2 == -1) {rot(o, d^1); return ;} 18 splay(ch[p][d2], k2); if(d == d2) rot(o, d^1); else rot(ch[o][d], d); rot(o, d^1); 19 } 20 void rev(int l, int r){ 21 splay(rt, r+2); splay(ch[rt][0], l); 22 if(ch[ch[rt][0]][1]) laz[ch[ch[rt][0]][1]]^=1; 23 } 24 25 void print(int o){ 26 pushdown(o); 27 if(ch[o][0]) print(ch[o][0]); 28 if(val[o] != n+1 && val[o]) printf("%d ", val[o]); 29 if(ch[o][1]) print(ch[o][1]); 30 } 31 32 void solve(){ 33 n=read(), m=read(); 34 for(int i=0; i <= n+1; i++) ins(rt, i), splay(rt, i+1); 35 for(int i=1; i <= m; i++){int l=read(), r=read(); rev(l, r);} 36 print(rt); 37 }
指针版（以前不压行的代码看着好长好啰嗦啊）
1 struct node 2 { 3 node* ch[2]; 4 int laz,s,v; 5 node(int v):v(v){s=1;ch[0]=ch[1]=NULL;laz=0;} 6 int cmp(int &k) 7 { 8 int ss=(ch[0] == NULL ? 0 : ch[0]->s); 9 if(k == ss+1) return -1; 10 if(k > ss) {k-=ss+1;return 1;} 11 return 0; 12 } 13 void maintain(){ 14 s=1; 15 if(ch[0]!=NULL) s+=ch[0]->s; 16 if(ch[1]!=NULL) s+=ch[1]->s; 17 } 18 void pushdown() 19 { 20 if(laz) 21 { 22 swap(ch[0],ch[1]); 23 if(ch[0]!=NULL) ch[0]->laz^=1; 24 if(ch[1]!=NULL) ch[1]->laz^=1; 25 laz=0; 26 } 27 } 28 }; 29 node* rt=NULL; 30 31 void rot(node* &o,int d) 32 { 33 o->pushdown();node* k=o->ch[d^1]; 34 k->pushdown();o->ch[d^1]=k->ch[d];k->ch[d]=o; 35 o->maintain();k->maintain();o=k; 36 } 37 38 void splay(node* &o,int k) 39 { 40 if(o == NULL) return ; 41 o->pushdown(); 42 int d=o->cmp(k); 43 if(d != -1) 44 { 45 46 node* p=o->ch[d];if(p == NULL) return ; 47 p->pushdown(); 48 int k2=k,d2=p->cmp(k2); 49 if(d2 != -1) 50 { 51 splay(p->ch[d2],k2); 52 if(d == d2) rot(o,d^1); 53 else rot(o->ch[d],d); 54 } 55 rot(o,d^1); 56 } 57 } 58 59 void ins(node* &o,int x) 60 { 61 if(o == NULL){o=new node(x);return ;} 62 int d=(x < o->v ? 0 : 1);ins(o->ch[d],x); 63 o->maintain(); 64 } 65 66 void rev(int l,int r) 67 { 68 splay(rt,r+2); 69 splay(rt->ch[0],l); 70 if(rt->ch[0]->ch[1] != NULL) 71 rt->ch[0]->ch[1]->laz^=1; 72 } 73 74 void print(node* o) 75 { 76 if(o==NULL) return ; 77 o->pushdown(); 78 print(o->ch[0]); 79 if(o->v != n+1 && o->v)printf("%d ",o->v); 80 print(o->ch[1]); 81 } 82 void solve(){ 83 n=read();m=read(); 84 for(int i=1;i<=n+2;i++) {ins(rt,i-1);splay(rt,i);} 85 while(m--){int l=read(),r=read(); rev(l,r);} 86 print(rt); 87 }