bzoj 1500 [NOI 2005] 维修数列

题目大意不多说了

貌似每个苦逼的acmer都要做一下这个splay树的模版题目吧

还是有很多操作的，估计够以后当模版了。。。。

 #include <cstdio>
 #include <cstring>
 #include <iostream>
 #include <algorithm>
 #include <cmath>

 using namespace std;
 const int N = ;
 const int INF = 0x3f3f3f3f;
 #define ls ch[x][0]
 #define rs ch[x][1]

 struct SplayTree{
     int ch[N][] , pre[N];
     int ml[N] , mr[N] , mm[N]; //区间最大
     int val[N] , sz[N] , sum[N] , size , rt;
     int rev[N] , to[N]; // lazy标记
     int del[N] , top; //内部保存删除的数的位置，然后可以从其中提取位置给新进入的元素
     int a[N];

     void push_up(int x)
     {
         sz[x] = sz[ls]+sz[rs]+;
         sum[x] = sum[ls]+sum[rs]+val[x];
         /*********************/
         ml[x] = max(ml[ls] , sum[ls]+val[x]+max(ml[rs] , ));
         mr[x] = max(mr[rs] , sum[rs]+val[x]+max(mr[ls] , ));
         mm[x] = max(mm[ls] , max(mm[rs] , max(ml[rs],)+max(mr[ls],)+val[x]));
         /*********************/
     }

     void push_down(int x)
     {
         if(rev[x]){
             if(ls){
                 rev[ls]^= ;
                 swap(ml[ls] , mr[ls]);
             }
             if(rs){
                 rev[rs]^= ;
                 swap(ml[rs] , mr[rs]);
             }
             swap(ls , rs);
             rev[x] = ;
         }
         /**to[x]的初始化要注意**/
         if(to[x]!=-INF){
             if(ls){
                 sum[ls] = sz[ls]*to[x];
                 ml[ls] = mr[ls] = mm[ls] = max(sum[ls] , to[x]);
                 val[ls] = to[ls] = to[x];
             }
             if(rs){
                 sum[rs] = sz[rs]*to[x];
                 ml[rs] = mr[rs] = mm[rs] = max(sum[rs] , to[x]);
                 val[rs] = to[rs] = to[x];
             }
             to[x] = -INF;
         }
     }

     void newNode(int &x , int fa , int v)
     {
         if(top != -)
             x = del[top--];
         else x = ++size;
         ch[x][] = ch[x][] = ;
         pre[x] = fa;
         val[x] = v , sz[x] = ;
         sum[x] = ml[x] = mr[x] = mm[x] = val[x];
         rev[x] =  , to[x] = -INF;
     }

     void build(int &x , int l , int r , int fa)
     {
         if(l>r) return;
         int m=(l+r)>>;
         newNode(x , fa , a[m]);
         build(ls , l , m- , x);
         build(rs , m+ , r , x);
         push_up(x);
     }

     void init(int n)
     {
         /*****因为所有点的最终叶子节点都下标设为了0，所以0上的数据要不影响整棵树*****/
         sz[] = sum[] = ch[][] = ch[][] = val[] = pre[] = ;
         to[] = ml[] = mr[] = mm[] = -INF;
         rev[] = ;
         top = - , rt = size = ;
         newNode(rt ,  , -INF);
         newNode(ch[rt][] , rt , -INF);
         build(ch[ch[rt][]][] ,  , n , ch[rt][]);
         push_up(ch[rt][]);
         push_up(rt);
     }

     void Rotate(int x , int f)
     {
         int y=pre[x] , z=pre[y];
         /**y要旋转到下方，下传lazy标记**/
         push_down(y);
         ch[y][!f] = ch[x][f] , pre[ch[x][f]] = y;
         ch[x][f] = y , pre[y] = x;
         ch[z][ch[z][]==y] = x , pre[x]=z;
         push_up(y);
         push_up(x);
     }

     void Splay(int x , int goal)
     {
         while(pre[x] != goal){
             if(pre[pre[x]] == goal) Rotate(x , ch[pre[x]][]==x);
             else{
                 int y = pre[x] , z = pre[y];
                 int f = ch[z][] == y;
                 if(ch[y][f] == x) Rotate(x , !f);
                 else Rotate(y,f);
                 Rotate(x , f);
             }
         }
         push_up(x);
         if(goal == ) rt = x;
     }

     int Select(int pos)
     {
         int x = rt;
         push_down(x);
         while(sz[ls]+ != pos){
             if(sz[ls]+>pos) x=ls;
             else{
                 pos = pos-sz[ls]-;
                 x = rs;
             }
             push_down(x);
         }
         return x;
     }
     /***从pos位置之后插入cnt个值***/
     void Insert(int pos , int cnt)
     {
         int x = Select(pos);
         Splay(x , );
         int y = Select(pos+);
         Splay(y , x);
         build(ch[y][] ,  , cnt , y);
         /***这里build将a[1~cnt]插入到splay树中，要push_up更新***/
         push_up(y);
         push_up(x);
     }
     /***回收被删除的数的位置***/
     void Recycle(int x)
     {
         if(x){
             del[++top]=x;
             Recycle(ls);
             Recycle(rs);
         }
     }

     void Delete(int s , int t)
     {
         int x = Select(s-) , y = Select(t+);
         Splay(x , ) , Splay(y , x);
         Recycle(ch[y][]);
         ch[y][] = ;
         /***这里y的左子树删除，明显子树数据改变，所以要重新push_up更新数据***/
         push_up(y);
         push_up(x);
     }
     /****将s~t区间内的所有值都修改为v****/
     void update(int s , int t , int v)
     {
         int x = Select(s-) , y = Select(t+);
         Splay(x , ) , Splay(y , x);
         int ptr = ch[y][];
         to[ptr]=v;
         val[ptr]=v;
         sum[ptr]=v*sz[ptr];
         ml[ptr] = mr[ptr] = mm[ptr] = max(sum[ptr] , v);
         return ;
     }

     void Reverse(int s , int t)
     {
         int x = Select(s-) , y = Select(t+);
         Splay(x , ) , Splay(y , x);
         int ptr = ch[y][];
         rev[ptr]^=;
         swap(ml[ptr] , mr[ptr]);
     }

     int querySum(int s , int t)
     {
         int x = Select(s-) , y =  Select(t+);
        // cout<<"x: "<<x<<" y: "<<y<<endl;
         Splay(x , ) , Splay(y , x);
         return sum[ch[y][]];
     }

     int queryMax()
     {
         int x = Select() , y = Select(sz[rt]);
         Splay(x , ) , Splay(y , x);
         return mm[ch[y][]];
     }
 }spt;
 int main()
 {
   //  freopen("a.in" , "r" , stdin);
     int n , m;
     char str[] ;
     int s , t , v , pos , k;
     while(~scanf("%d%d" , &n , &m))
     {
         for(int i= ; i<=n ; i++) scanf("%d" , &spt.a[i]);
         spt.init(n);
         /*
         for(int i=0 ; i<=spt.size ; i++){
             cout<<"i: "<<i<<" sum: "<<spt.sum[i]<<" l: "<<spt.ch[i][0]<<" lv: "<<spt.val[spt.ch[i][0]]<<" r: "<<spt.ch[i][1]<<" rv: "<<spt.val[spt.ch[i][1]]<<endl;
         }*/
         for(int i= ; i<m ; i++){
             scanf("%s" , str);
             if(str[] == 'I'){
                 scanf("%d%d" , &pos , &k);
                 for(int i= ; i<=k ; i++) scanf("%d" , &spt.a[i]);
                 spt.Insert(pos+ , k);
             }
             else if(str[]=='D'){
                 scanf("%d%d" , &pos , &k);
                 spt.Delete(pos+ , pos+k);
             }
             else if(str[] == 'M' && str[] == 'K'){
                 scanf("%d%d%d" , &pos , &k , &v);
                 spt.update(pos+ , pos+k , v);
             }
             else if(str[] == 'R'){
                 scanf("%d%d" , &pos , &k);
                 spt.Reverse(pos+ , pos+k);
             }
             else if(str[] == 'G'){
                 scanf("%d%d" , &pos , &k);
                 printf("%d\n" , spt.querySum(pos+ , pos+k));
             }
             else{
                 /****这里不能直接用spt.mm[rt]作为答案，因为为了方便查询，
                 我们增加了两个不包含在本身数组的点，直接spt.mm[rt]会把这两个点也算进来***/
                 printf("%d\n" , spt.queryMax());
             }
         }
     }
     return ;
 }