HDU 3308 LCIS

[align=left]Problem Description[/align]
Given n integers.

You have two operations:

U A B: replace the Ath number by B. (index counting from 0)

Q A B: output the length of the longest consecutive increasing subsequence (LCIS) in [a, b].

 

[align=left]Input[/align]
T in the first line, indicating the case number.

Each case starts with two integers n , m(0<n,m<=105).

The next line has n integers(0<=val<=105).

The next m lines each has an operation:

U A B(0<=A,n , 0<=B=105)

OR

Q A B(0<=A<=B< n).

 

[align=left]Output[/align]
For each Q, output the answer.
 

[align=left]Sample Input[/align]

1
10 10
7 7 3 3 5 9 9 8 1 8
Q 6 6
U 3 4
Q 0 1
Q 0 5
Q 4 7
Q 3 5
Q 0 2
Q 4 6
U 6 10
Q 0 9

 

[align=left]Sample Output[/align]

1
1
4
2
3
1
2
5

 

[align=left]Author[/align]
shǎ崽
 

[align=left]Source[/align]
HDOJ Monthly Contest – 2010.02.06

 

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线段树单点更新，维护线段树的最长上升子序列
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std ;

#define ll o << 1
#define rr o << 1 | 1
#define lson l , m , ll
#define rson m + 1 , r , rr

const int maxN = 1000000 ;

int lnum[maxN] , rnum[maxN] ;
int lmax[maxN] , rmax[maxN] , mmax[maxN] ;

int max ( const int X , const int Y )
{
if ( X > Y ) return X ;
return Y ;
}

int min ( const int X , const int Y )
{
if ( X < Y ) return X ;
return Y ;
}

void PushUp ( int o , int len )
{
lnum[o] = lnum[ll] ;
rnum[o] = rnum[rr] ;
lmax[o] = lmax[ll] ;
rmax[o] = rmax[rr] ;
mmax[o] = max ( mmax[ll] , mmax[rr] ) ;
if ( rnum[ll] < lnum[rr] )
{
mmax[o] = max ( mmax[o] , rmax[ll] + lmax[rr] ) ;
if ( lmax[ll] == len - ( len >> 1 ) )
{
lmax[o] += lmax[rr] ;
}
if ( rmax[rr] == ( len >> 1 ) )
{
rmax[o] += rmax[ll] ;
}
}
}

void Build ( int l , int r , int o )
{
if ( l == r )
{
int x ;
scanf ( "%d" , &x ) ;
lnum[o] = rnum[o] = x ;
lmax[o] = mmax[o] = rmax[o] = 1 ;
return ;
}
int m = ( l + r ) >> 1 ;
Build ( lson ) ;
Build ( rson ) ;
PushUp ( o , r - l + 1 ) ;
}

void Update ( int x , int v , int l , int r , int o )
{
if ( l == r )
{
lnum[o] = rnum[o] = v ;
lmax[o] = mmax[o] = rmax[o] = 1 ;
return ;
}
int m = ( l + r ) >> 1 ;
if ( x <= m ) Update ( x , v , lson ) ;
else Update ( x , v , rson ) ;
PushUp ( o , r - l + 1 ) ;
}

int Query ( int L , int R , int l , int r , int o )
{
if ( L <= l && r <= R ) return mmax[o] ;
int m = ( l + r ) >> 1 ;
int tmp1 = 0 , tmp2 = 0 , tmp3 = 0 ;
if ( L <= m ) tmp1 = Query ( L , R , lson ) ;
if ( m < R ) tmp2 = Query ( L , R , rson ) ;
if ( L <= m && m < R && rnum[ll] < lnum[rr] ) tmp3 = min ( m - L + 1 , rmax[ll] ) + min ( lmax[rr] , R - m ) ;
return max ( max ( tmp1 , tmp2 ) , tmp3 ) ;
}

void work ()
{
int n , m , First , Second ;
char ch[5] ;
scanf ( "%d%d" , &n , &m ) ;
Build ( 1 , n , 1 ) ;
while ( m -- )
{
scanf ( "%s%d%d" , ch , &First , &Second ) ;
if ( ch[0] == 'U' ) Update ( First + 1 , Second , 1 , n , 1 ) ;
else printf ( "%d\n" , Query ( First + 1 , Second + 1 , 1 , n , 1 ) ) ;
}
}

int main ()
{
int T ;
scanf ( "%d" , &T ) ;
while ( T -- )
{
work () ;
}
return 0 ;
}