题意:
初始给一个长度为n的数组,维护以下操作:
1.插入一段数字:p tot a1...atot表示在位置p后面插入tot个数字
2.删除一段数字:p tot表示在位置p开始删除tot个数字
3.修改一段数字:p tot c表示在位置p开始修改tot个数字为c
4.反转一段数字:p tot表示将在位置p开始长度为tot的区间反转
5.求和一段数字:p tot表示求从位置p开始长度为tot的区间和
6.求整个数组的最大子列和
思路:
因为插入数字和删除数字比较多,所以考虑单个单个以log的时间复杂度进行插入和删除,必定会超时,所以我们采用以下策略来应对:
1.将数字全部输入“线性建树”建成一颗小树z,将原来的树在p处拆开为x,y,然后合并x,z,y
2.将要删除的数字从树中拆出来单独一颗树z,然后将这些树的“下标回收”
3.将要修改的区间从树中拆出来单独修改
4.将要反转的区间从树中拆出来单独反转
5.将要求和的区间从树中拆出来单独求和
6.Push_up细心维护,和线段区间合并维护最大子列和类似
C++代码:
#include<map>
#include<set>
#include<stack>
#include<cmath>
#include<queue>
#include<vector>
#include<string>
#include<cstdio>
#include<cstring>
#include<complex>
#include<iostream>
#include<algorithm>
using namespace std;
#define ls ftr[k].l
#define rs ftr[k].r
typedef double DB;
typedef long long LL;
typedef complex<double>CD;
const int maxn = 500010;
const int mod = 1e9+7;
const int inf = 0x3f3f3f3f;
void Mod( int &x ){ x%=mod; }
int Min( int a , int b ){ return a<b?a:b; }
int Max( int a , int b ){ return a>b?a:b; }
int Random(){ static int seed = 703; return seed=(int)(seed*48271LL%2147483647); }
int root,sizes,a[maxn];
queue<int>Q;
struct FHQ_Treap
{
int l,r;
int v,rnd;
int sizes;
int sum,rev,cnt;
int lmax,rmax,maxx;
}ftr[maxn];
void Revone( int k )
{
if ( !k )
return;
ftr[k].rev ^= 1;
swap ( ls , rs );
swap ( ftr[k].lmax , ftr[k].rmax );
}
void Covone( int k , int s )
{
if ( !k )
return;
ftr[k].v = s;
ftr[k].sum = ftr[k].sizes*s;
ftr[k].cnt = s;
ftr[k].lmax = ftr[k].rmax = ftr[k].maxx = Max ( s , s*ftr[k].sizes );
}
void Push_up( int k )
{
if ( !k )
return;
ftr[k].sizes = ftr[ls].sizes+ftr[rs].sizes+1;
ftr[k].sum = ftr[ls].sum+ftr[rs].sum+ftr[k].v;
ftr[k].maxx = Max ( Max( 0 , ftr[ls].rmax )+ftr[k].v+Max( 0 , ftr[rs].lmax ) , Max( ftr[ls].maxx , ftr[rs].maxx ) );
ftr[k].lmax = Max ( ftr[ls].lmax , ftr[ls].sum+ftr[k].v+Max( 0 , ftr[rs].lmax ) );
ftr[k].rmax = Max ( ftr[rs].rmax , ftr[rs].sum+ftr[k].v+Max( 0 , ftr[ls].rmax ) );
}
void Push_down( int k )
{
if ( !k )
return;
if ( ftr[k].cnt!=inf )
Covone( ls , ftr[k].cnt ),Covone( rs , ftr[k].cnt );
if ( ftr[k].rev )
Revone( ls ),Revone( rs );
ftr[k].cnt = inf;
ftr[k].rev = 0;
}
void Build( int &k , int s )
{
if ( !Q.empty() )
k = Q.front(),Q.pop();
else
k = ++sizes;
ftr[k].l = 0;
ftr[k].r = 0;
ftr[k].v = s;
ftr[k].rnd = Random();
ftr[k].sizes = 1;
ftr[k].sum = s;
ftr[k].rev = 0;
ftr[k].cnt = inf;
ftr[k].lmax = s;
ftr[k].rmax = s;
ftr[k].maxx = s;
}
void Split( int k , int &l , int &r , int s )
{
if ( s==0 )
l = 0,r = k;
else if ( s==ftr[k].sizes )
l = k,r = 0;
else if ( s<=ftr[ls].sizes )
Push_down( r=k ),Split( ls , l , ls , s ),Push_up( k );
else
Push_down( l=k ),Split( rs , rs , r , s-ftr[ls].sizes-1 ),Push_up( k );
}
void Merge( int &k , int l , int r )
{
if ( l==0||r==0 )
k = l+r;
else if ( ftr[l].rnd<ftr[r].rnd )
Push_down( k=l ),Merge( rs , rs , r ),Push_up( k );
else
Push_down( k=r ),Merge( ls , l , ls ),Push_up( k );
}
void Cov( int l , int r , int s )
{
int x,y,z;
Split( root , x , y , r );
Split( x , z , x , l-1 );
Covone( x , s );
Merge( x , z , x );
Merge( root , x , y );
}
void Rev( int l , int r )
{
int x,y,z;
Split( root , x , y , r );
Split( x , z , x , l-1 );
Revone( x );
Merge( x , z , x );
Merge( root , x , y );
}
int Sum( int l , int r )
{
int x,y,z,ans;
Split( root , x , y , r );
Split( x , z , x , l-1 );
ans = ftr[x].sum;
Merge( x , z , x );
Merge( root , x , y );
return ans;
}
void Back( int k )
{
if ( !k )
return;
Back( ls );
Q.push( k );
Back( rs );
}
void Delete( int l , int r )
{
int x,y,z;
Split( root , x , y , r );
Split( x , z , x , l-1 );
Merge( root , z , y );
Back( x );
}
void New( int &k , int l , int r )
{
if ( l>r )
{
k = 0;
return;
}
int mid = ( l+r )>>1;
Build( k , a[mid] );
New ( ls , l , mid-1 );
New ( rs , mid+1 , r );
Push_up( k );
}
int main()
{
for ( int n,m ; scanf ( "%d%d" , &n , &m )==2 ; )
{
ftr[0].maxx = -inf;
sizes = root = 0;
for ( int i=1 ; i<=n ; i++ )
scanf ( "%d" , &a[i] );
New ( root , 1 , n );
for ( int i=1 ; i<=m ; i++ )
{
char s[15];
int p,tot,c,x,y;
scanf ( "%s" , s );
if ( s[0]=='I' )
{
scanf ( "%d%d" , &p , &tot );
for ( int j=1 ; j<=tot ; j++ )
scanf ( "%d" , &a[j] );
New ( c , 1 , tot );
Split( root , x , y , p );
Merge( x , x , c );
Merge( root , x , y );
}
else if ( s[0]=='D' )
{
scanf ( "%d%d" , &p , &tot );
Delete( p , p+tot-1 );
}
else if ( s[0]=='M'&&s[2]=='K' )
{
scanf ( "%d%d%d" , &p , &tot , &c );
Cov ( p , p+tot-1 , c );
}
else if ( s[0]=='R' )
{
scanf ( "%d%d" , &p , &tot );
Rev ( p , p+tot-1 );
}
else if ( s[0]=='G' )
{
scanf ( "%d%d" , &p , &tot );
printf ( "%d\n" , Sum( p , p+tot-1 ) );
}
else
printf ( "%d\n" , ftr[root].maxx );
}
}
return 0;
}