oj.uz

답안 #868425

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
868425 2023-10-31T13:11:07 Z chonka Chorus (JOI23_chorus) C++17
0 / 100
 2 ms 8540 KB 
#include<bits/stdc++.h>
using namespace std ;
typedef long long ll ;
typedef unsigned long long ull ;
typedef pair < int , int > pii ;
typedef vector < int > vi ;
#define fi first
#define se second
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()

const int MAXN = 1e6 + 7 ;

int n , k ;
int a[ MAXN ] , b[ MAXN ] ;
int lw[ MAXN ] , ori[ MAXN ] ;
ll pref[ MAXN ] ;

inline ll calc ( int l , int r ) {
    if ( r <= ori[ l ] ) { return 0 ; }
    int aux_st = max ( ori[ l ] , l - 1 ) ;
    return ( pref[ r ] - pref[ aux_st ] ) + - 1LL * ( r - aux_st ) * ( l - 1 ) ;
}

ll dp[ MAXN ] ;
int ctr[ MAXN ] ;


int get_fst ( int x , int y ) {
    int l , r , mid ;
    l = max ( x , y ) + 1 , r = n ;
    if ( dp[ x ] + calc ( x + 1 , n ) < dp[ y ] + calc ( y + 1 , n ) ) { return n + 1 ; }
    while ( l < r ) {
        mid = ( l + r ) / 2 ;
        if ( dp[ x ] + calc ( x + 1 , mid ) < dp[ y ] + calc ( y + 1 , mid ) ) { l = mid + 1 ; }
        else { r = mid ; }
    }
    return l ;
}


pair < ll , int > f ( ll sr ) {
    deque < int > q ;
    q.push_front ( 0 ) ;
    for ( int i = 1 ; i <= n ; ++ i ) {
        while ( (int)q.size ( ) >= 2 && get_fst ( q[ 0 ] , q[ 1 ] ) <= i ) {
            q.pop_front ( ) ;
        }
        while ( (int)q.size ( ) >= 3 && get_fst ( q[ 0 ] , q[ 1 ] ) > get_fst ( q[ 1 ] , q[ 2 ] ) ) {
            int x = q[ 0 ] ;
            q.pop_front ( ) ; q.pop_front ( ) ;
            q.push_front ( x ) ;
        }
        int x = q.front ( ) ;
        dp[ i ] = dp[ x ] + calc ( x + 1 , i ) + sr ;
        ctr[ i ] = ctr[ x ] + 1 ;
        while ( (int)q.size ( ) >= 1 && dp[ q.back ( ) ] + calc ( q.back ( ) + 1 , i ) >= dp[ i ] ) { q.pop_back ( ) ; }
        q.push_back ( i ) ;
    }
    return { dp[ n ] , ctr[ n ] } ;
}

void solve ( ) {
    cin >> n >> k ;
    string s ; cin >> s ;
    int pos1 = 0 , pos2 = 0 ;
    for ( int i = 1 ; i <= 2 * n ; ++ i ) {
        if ( s[ i - 1 ] == 'A' ) { a[ ++ pos1 ] = i ; }
        else { b[ ++ pos2 ] = i ; }
    }
    int tp = 0 ;
    for ( int i = 1 ; i <= n ; ++ i ) {
        while ( tp < n && b[ tp + 1 ] < a[ i ] ) { ++ tp ; }
        lw[ i ] = tp ;
        pref[ i ] = pref[ i - 1 ] + lw[ i ] ;
    }
    pref[ n + 1 ] = pref[ n ] ;
    tp = 0 ;
    for ( int i = 1 ; i <= n ; ++ i ) {
        while ( tp < n && lw[ tp + 1 ] < i ) { ++ tp ; }
        ori[ i ] = tp ;
    }
    ll l , r , mid ;
    l = -( 1LL << 50 ) , r = ( 1LL << 50 ) ;
    ll ans = ( 1LL << 50 ) ;
    while ( l < r ) {
        mid = ( l + r ) / 2 ;
        auto [ ret , cnt ] = f ( mid ) ;
        if ( cnt <= k ) {
            ans = min ( ans , ret - cnt * mid ) ;
            r = mid - 1 ; 
        }
        else { l = mid + 1 ; }
    }
    auto [ ret , cnt ] = f ( l ) ;
    if ( cnt <= k ) { ans = min ( ans , ret - cnt * l ) ; }
    cout << ans << "\n" ;
}

int main ( ) {
    ios_base :: sync_with_stdio ( false ) ;
    cin.tie ( NULL ) ;
    int t = 1 ; // cin >> t ;
    while ( t -- ) { solve ( ) ; }
    return 0 ;
}

Subtask #1
0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 8540 KB Output is correct
2 Correct 2 ms 8540 KB Output is correct
3 Correct 1 ms 8540 KB Output is correct
4 Correct 1 ms 8540 KB Output is correct
5 Correct 1 ms 8540 KB Output is correct
6 Incorrect 1 ms 8540 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
0 / 24.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 8540 KB Output is correct
2 Correct 2 ms 8540 KB Output is correct
3 Correct 1 ms 8540 KB Output is correct
4 Correct 1 ms 8540 KB Output is correct
5 Correct 1 ms 8540 KB Output is correct
6 Incorrect 1 ms 8540 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 8540 KB Output is correct
2 Correct 2 ms 8540 KB Output is correct
3 Correct 1 ms 8540 KB Output is correct
4 Correct 1 ms 8540 KB Output is correct
5 Correct 1 ms 8540 KB Output is correct
6 Incorrect 1 ms 8540 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #4
0 / 26.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 8540 KB Output is correct
2 Correct 2 ms 8540 KB Output is correct
3 Correct 1 ms 8540 KB Output is correct
4 Correct 1 ms 8540 KB Output is correct
5 Correct 1 ms 8540 KB Output is correct
6 Incorrect 1 ms 8540 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #5
0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 8540 KB Output is correct
2 Correct 2 ms 8540 KB Output is correct
3 Correct 1 ms 8540 KB Output is correct
4 Correct 1 ms 8540 KB Output is correct
5 Correct 1 ms 8540 KB Output is correct
6 Incorrect 1 ms 8540 KB Output isn't correct
7 Halted 0 ms 0 KB -