BZOJ 1493 NOI 2007 项链工厂 Splay

题目大意：有一个很长的带颜色的项链，要求你快速的维护一种数据结构，他可以：

1.把序列的后k个放在前面。

2.将区间2~cnt的珠子翻转。

3.将位置i和位置j的珠子互换。

4.将区间i到j染色成k

5.输出整个序列的颜色块的个数

6.输出从i到j的颜色块的个数。

思路：Splay。有些不好处理的是要时刻想着这是一个环，所以所有的计算颜色块的个数的时候要考虑收尾的颜色是否相同。还有从序列的尾部到转一圈回去的情况。

就因为这个题我的代码有个小小小小的问题，花了仨小时的时间带着数据才把错找到。。简直不知道说些什么好。。啊啊啊啊以后写题一定要细致啊！！！

CODE：

#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#define MAX 500010using namespace std;struct Complex{int col,cnt_col,l_col,r_col;int size;Complex *son[2],*father;bool reverse,change;int change_into;void Combine(Complex *a,bool dir) {son[dir] = a;a->father = this;}bool Check() {return father->son[1] == this;}void Reverse();void Paint(int val);void PushUp();void PushDown();}*nil = new Complex(),*root;int cnt,cols,asks;int src[MAX];char cmd[10];void Pretreatment();inline Complex *NewComplex(int val);Complex *BuildTree(int l,int r);Complex *Kth(Complex *a,int k);inline void Rotate(Complex *a,bool dir);inline void Splay(Complex *a,Complex *aim);inline void SplaySeg(int x,int y);int main(){Pretreatment();cin >> cnt >> asks;for(int i = 1;i <= cnt; ++i)scanf("%d",&src[i]);root = BuildTree(0,cnt + 1);root->father = nil;cin >> asks;for(int x,y,z,i = 1;i <= asks; ++i) {scanf("%s",cmd);if(cmd[0] == 'R') {scanf("%d",&x);SplaySeg(cnt - x + 1,cnt);Complex *temp = root->son[1]->son[0];temp->father = nil;root->son[1]->son[0] = nil;root->son[1]->PushUp(),root->PushUp();Splay(Kth(root,1),nil);Splay(Kth(root,2),root);root->son[1]->Combine(temp,false);}else if(cmd[0] == 'F') {SplaySeg(2,cnt);root->son[1]->son[0]->Reverse();}else if(cmd[0] == 'S') {scanf("%d%d",&x,&y);if(x == y)continue;if(x > y)swap(x,y);Splay(Kth(root,x + 1),nil);Splay(Kth(root,y + 1),root);int temp = root->son[1]->col;root->son[1]->col = root->col;root->son[1]->PushUp(),root->PushUp();root->col = temp;}else if(cmd[0] == 'P') {scanf("%d%d%d",&x,&y,&z);if(y >= x) {SplaySeg(x,y);root->son[1]->son[0]->Paint(z);}else {SplaySeg(x,cnt);root->son[1]->son[0]->Paint(z);root->son[1]->PushUp(),root->PushUp();SplaySeg(1,y);root->son[1]->son[0]->Paint(z);}}else if(cmd[0] == 'C' && cmd[1] == '\0') {SplaySeg(1,cnt);int ans = root->son[1]->son[0]->cnt_col;ans -= (root->son[1]->son[0]->l_col == root->son[1]->son[0]->r_col);if(!ans)++ans;printf("%d\n",ans);continue;}else {scanf("%d%d",&x,&y);if(y >= x) {SplaySeg(x,y);printf("%d\n",root->son[1]->son[0]->cnt_col);}else {int ans = 0;SplaySeg(x,cnt);ans = root->son[1]->son[0]->cnt_col;SplaySeg(1,y);ans += root->son[1]->son[0]->cnt_col;SplaySeg(1,cnt);ans -= (root->son[1]->son[0]->l_col == root->son[1]->son[0]->r_col);printf("%d\n",ans);}continue;}root->son[1]->PushUp(),root->PushUp();}return 0;}void Complex:: Reverse() {if(!col)return ;reverse ^= 1;swap(son[0],son[1]);swap(l_col,r_col);}void Complex:: Paint(int val) {if(!col)return ;change = true;change_into = val;l_col = r_col = col = val;cnt_col = 1;}void Complex:: PushUp() {if(this == nil)return ;size = son[0]->size + son[1]->size + 1;if(!col)return ;cnt_col = 1;l_col = r_col = col;if(son[0]->col) {cnt_col += son[0]->cnt_col - (son[0]->r_col == col);l_col = son[0]->l_col;}if(son[1]->col) {cnt_col += son[1]->cnt_col - (son[1]->l_col == col);r_col = son[1]->r_col;}}void Complex:: PushDown() {if(this == nil)return ;if(reverse) {son[0]->Reverse();son[1]->Reverse();reverse = false;}if(change) {son[0]->Paint(change_into);son[1]->Paint(change_into);change = false;}}void Pretreatment() {nil->size = 0;nil->col = nil->l_col = nil->r_col = 0;nil->cnt_col = 0;nil->father = nil->son[0] = nil->son[1] = nil;}inline Complex *NewComplex(int val){Complex *re = new Complex();re->col = re->l_col = re->r_col = val;re->size = 1;if(val) re->cnt_col = 1;re->son[0] = re->son[1] = nil;return re;}Complex *BuildTree(int l,int r){if(l > r)return nil;int mid = (l + r) >> 1;Complex *re = NewComplex(src[mid]);re->Combine(BuildTree(l,mid - 1),false);re->Combine(BuildTree(mid + 1,r),true);re->PushUp();return re;}Complex *Kth(Complex *a,int k){a->PushDown();if(a->son[0]->size >= k)return Kth(a->son[0],k);k -= a->son[0]->size;if(k == 1)return a;return Kth(a->son[1],k - 1);}inline void Rotate(Complex *a,bool dir){Complex *f = a->father;f->PushDown(),a->PushDown();f->son[!dir] = a->son[dir];f->son[!dir]->father = f;a->son[dir] = f;a->father = f->father;f->father->son[f->Check()] = a;f->father = a;f->PushUp();if(root == f)root = a;}inline void Splay(Complex *a,Complex *aim){while(a->father != aim) {if(a->father->father == aim)Rotate(a,!a->Check());else if(!a->father->Check()) {if(!a->Check())Rotate(a->father,true),Rotate(a,true);elseRotate(a,false),Rotate(a,true);}else {if(a->Check())Rotate(a->father,false),Rotate(a,false);elseRotate(a,true),Rotate(a,false);}}a->PushUp();}inline void SplaySeg(int x,int y){x++,y++;Splay(Kth(root,x - 1),nil);Splay(Kth(root,y + 1),root);}