bzoj 1500 维修数列

splay乱搞。

调了两个多小时。。。这辈子再也不想写splay了。。。

维护左边最大连续和右边最大连续，维护两个标记，无脑push_down、push_up就行了。

注意最大连续和至少要包含一个数。

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #define N 500010
 #define M 5000005
 #define inf 0x3f3f3f3f
 #define lc(x) ch[x][0]
 #define rc(x) ch[x][1]
 using namespace std;
 int n,m;
 int cnt;
 int a[N],root,ch[N][],tmproot;
 int sum[N],ls[N],rs[N],mx[N],ji[N];
 int lazy[N],size[N],zhi[N],fa[N];
 int s[M],tot2;
 inline int mxx(int x,int y)
 {
     if(x>y)return x;return y;
 }
 // ls 左边最大 rs 右边最大
 void push_up(int x)
 {
     size[x]=size[lc(x)]+size[rc(x)]+;
     sum[x]=sum[lc(x)]+sum[rc(x)]+zhi[x];
     mx[x]=mxx(mx[lc(x)],mxx(mx[rc(x)],zhi[x]+rs[lc(x)]+ls[rc(x)]));
     ls[x]=mxx(,mxx(ls[lc(x)],sum[lc(x)]+zhi[x]+ls[rc(x)]));
     rs[x]=mxx(,mxx(rs[rc(x)],sum[rc(x)]+zhi[x]+rs[lc(x)]));
     return ;
 }
 void push_down(int x)
 {
     int l=ch[x][];int r=ch[x][];
     if(ji[x]!=-)
     {
         ji[l]=ji[r]=ji[x];
         sum[l]=size[l]*ji[x];sum[r]=size[r]*ji[x];
         zhi[l]=zhi[r]=ji[x];
         if(ji[x]>)ls[l]=rs[l]=mx[l]=sum[l],ls[r]=rs[r]=mx[r]=sum[r];
         else ls[l]=rs[l]=,ls[r]=rs[r]=,mx[l]=mx[r]=ji[x];
         ji[x]=-;
     }
     if(lazy[x]==)
     {
         lazy[l]^=;lazy[r]^=;
         swap(ch[l][],ch[l][]);
         swap(ch[r][],ch[r][]);
         swap(ls[l],rs[l]);swap(ls[r],rs[r]);
         lazy[x]=;
     }
     sum[]=ls[]=rs[]=;mx[]=-inf;
     return ;
 }
 void build(int x,int l,int r)
 {
     if(l==r)
     {
         size[x]=;
         sum[x]=zhi[x]=mx[x]=a[l];
         rs[x]=ls[x]=max(,a[l]);
         return ;
     }
     int mid=(l+r)>>;
     if(l!=mid)
     {
         if(tot2)ch[x][]=s[tot2--];
         else ch[x][]=++cnt;
         fa[ch[x][]]=x,build(ch[x][],l,mid-);
     }
     if(tot2)ch[x][]=s[tot2--];
     else ch[x][]=++cnt;
     fa[ch[x][]]=x,build(ch[x][],mid+,r);
     zhi[x]=a[mid];
     push_up(x);
 }
 void rotate(int p)
 {
     int q=fa[p],y=fa[q],x=(ch[q][]==p);
     ch[q][x]=ch[p][x^];fa[ch[q][x]]=q;
     ch[p][x^]=q;fa[q]=p;
     fa[p]=y;
     if(y)
     {
         if(ch[y][]==q)ch[y][]=p;
         else ch[y][]=p;
     }
     push_up(q);
     return ;
 }
 void splay(int x,int yy)
 {
     for(int y;y=fa[x];rotate(x))
     {
         if(y==yy)break;
         if(fa[y]!=yy)
         {
             if((lc(fa[y])==y&&lc(y)==x)||(rc(fa[y])==y&&rc(y)==x))rotate(y);
             else rotate(x);
         }
     }
     push_up(x);
     if(!yy)root=x;
 }
 int find(int k,int x)
 {
     push_down(k);
     int l=lc(k),r=rc(k);
     if(size[l]+==x)return k;
     if(size[l]+>x)return find(l,x);
     else return find(r,x-size[l]-);
 }
 char c[];
 void dfs(int x)
 {
     if(!x)return ;
     cout<<zhi[x]<<' '<<sum[x]<<' '<<size[x]<<endl;
     dfs(ch[x][]);dfs(ch[x][]);
 }
 void del(int x)
 {
     if(!x)return ;
     s[++tot2]=x;ji[x]=-;lazy[x]=;sum[x]=;
     del(ch[x][]);del(ch[x][]);
     ch[x][]=ch[x][]=;fa[x]=;size[x]=;
 }
 int main()
 {
     scanf("%d%d",&n,&m);
     mx[]=-inf;
     for(int i=;i<=n;i++)scanf("%d",&a[i]);
    for(int i=;i<N;i++)ji[i]=-;
     root=++cnt;
     a[]=a[n+]=;
     build(cnt,,n+);
     int t1,t2,t3,t4,t5,t6;
     for(int i=;i<=m;i++)
     {
         scanf("%s",c);
         if(c[]=='I')
         {
             scanf("%d%d",&t1,&t2);
             for(int j=;j<=t2;j++)scanf("%d",&a[j]);
             if(tot2)tmproot=s[tot2--];
             else tmproot=++cnt;
             build(tmproot,,t2);
             t1++;t3=find(root,t1);
             splay(t3,);
             t4=ch[t3][];push_down(t4);
             while(ch[t4][])t4=ch[t4][],push_down(t4);
             splay(t4,t3);ch[t4][]=tmproot;fa[tmproot]=t4;push_up(t4);push_up(t3);
         }
         else if(c[]=='D')
         {
             scanf("%d%d",&t1,&t2);
             t3=find(root,t1);
             splay(t3,);
             t2=t2+t1+;
             t4=find(root,t2);
             splay(t4,t3);
             del(ch[t4][]);
             ch[t4][]=;
             push_up(t4);push_up(t3);
         }
         else if(c[]=='R')
         {
             scanf("%d%d",&t1,&t2);
             t3=find(root,t1);splay(t3,);t2=t2+t1+;t4=find(root,t2);
             splay(t4,t3);
             t5=ch[t4][];
             lazy[t5]^=;swap(ch[t5][],ch[t5][]);swap(ls[t5],rs[t5]);
             push_up(t4);push_up(t3);
         }
         else if(c[]=='G')
         {
             scanf("%d%d",&t1,&t2);
             t3=find(root,t1);
             splay(t3,);t2=t2+t1+;
             t4=find(root,t2);
             splay(t4,t3);
             printf("%d\n",sum[ch[t4][]]);
         }
         else if(c[]=='M'&&c[]=='S')
         {
             t1=find(root,);
             splay(t1,);
             t2=find(root,size[root]);
             splay(t2,t1);
             printf("%d\n",mx[ch[t2][]]);
         }
         else
         {
             scanf("%d%d%d",&t1,&t2,&t6);
             t3=find(root,t1);splay(t3,);t2=t2+t1+;
             t4=find(root,t2);
             splay(t4,t3);
             t5=ch[t4][];
             ji[t5]=t6;zhi[t5]=t6;sum[t5]=size[t5]*t6;
             if(t6>)ls[t5]=rs[t5]=mx[t5]=sum[t5];
             else ls[t5]=rs[t5]=,mx[t5]=t6;
             push_up(t4);push_up(t3);
         }
     }
     return ;
 }