Submission #624156

#	Time	Username	Problem	Language	Result	Execution time	Memory
624156		mdn2002	Sorting (IOI15_sorting)	C++14	54 / 100	80 ms	720 KiB

sorting

#include "sorting.h"
#include<bits/stdc++.h>
using namespace std;

int n , m , a [2003] , aa [2003] , x [20004] , y [20004] , dis [20004] , wrdis [20004] , wra [20004] , P [20004] , Q [20004];


bool ck ( int xx )
{
    for ( int i = 1 ; i <= n ; i ++ )
    {
        a [i] = aa [i];
        wra [ a [i] ] = i;
    }
    int mm = xx;
    for ( int i = 1 ; i <= n ; i ++ )
    {
        dis [i] = i;
        wrdis [ dis [i] ] = i;
    }
    for ( int j = mm - 1 ; j >= 0 ; j -- )
    {
        swap ( dis [ x [j] ] , dis [ y [j] ] );
        swap ( wrdis [ dis [ x [j] ] ] , wrdis [ dis [ y [j] ] ] );
    }
    set < int > s;
    for ( int i = 1 ; i <= n ; i ++ )
    {
        if ( dis [i] != a [i] ) s . insert ( dis [i] );
    }

    for ( int i = 1 ; i <= mm ; i ++ )
    {

        int f = 0;
        for ( int j = 1 ; j <= n ; j ++ )
        {
            if ( a [j] != j ) f = 1;
        }
        if ( f == 0 ) return 1;

        swap ( a [ x [ i - 1 ] ] , a [ y [ i - 1 ] ] );
        swap ( wra [ a [ x [ i - 1 ] ] ] , wra [ a [ y [ i - 1 ] ] ] );
        swap ( dis [ x [ i - 1 ] ] , dis [ y [ i - 1 ] ] );
        swap ( wrdis [ dis [ x [ i - 1 ] ] ] , wrdis [ dis [ y [ i - 1 ] ] ] );

        if ( s . size () )
        {

            int x = * s . begin () , z = wra [x];
            s . erase ( s . begin () );

            swap ( a [ wrdis [x] ] , a [z] );
            swap ( wra [ a [ wrdis [x] ] ] , wra [ a [z] ] );
            if ( a [z] == dis [z] ) s . erase ( s . lower_bound ( dis [z] ) );
            
        }
    }
    return 0;
}
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {

    n = N;
    for ( int i = 1 ; i <= n ; i ++ )
    {
        a [i] = S [ i - 1 ];
        a [i] ++;
        aa [i] = a [i];
    }
    m = M;
    for ( int i = 0 ; i < m ; i ++ )
    {
        x [i] = X [i] , y [i] = Y [i];
        x [i] ++ , y [i] ++;
    }

    int l = 0 , rr = m + 1 , mid;
    while ( l < rr )
    {
        mid = ( l + rr ) / 2;
        if ( ck ( mid ) ) rr = mid;
        else l = mid + 1;
    }
    m = l;

    for ( int i = 1 ; i <= n ; i ++ )
    {
        a [i] = aa [i];
        wra [ a [i] ] = i;
    }
    for ( int i = 1 ; i <= n ; i ++ )
    {
        dis [i] = i;
        wrdis [i] = i;
    }
    for ( int j = m - 1 ; j >= 0 ; j -- )
    {
        swap ( dis [ x [j] ] , dis [ y [j] ] );
        swap ( wrdis [ dis [ x [j] ] ] , wrdis [ dis [ y [j] ] ] );
    }

    set < int > s;
    for ( int i = 1 ; i <= n ; i ++ )
    {
        if ( dis [i] != a [i] ) s . insert ( dis [i] );
    }

    int r = 0;
    for ( int i = 1 ; i <= m ; i ++ )
    {

        int f = 0;
        for ( int j = 1 ; j <= n ; j ++ )
        {
            if ( a [j] != j ) f = 1;
        }
        if ( f == 0 ) return r;

        swap ( a [ x [ i - 1 ] ] , a [ y [ i - 1 ] ] );
        swap ( wra [ a [ x [ i - 1 ] ] ] , wra [ a [ y [ i - 1 ] ] ] );
        swap ( dis [ x [ i - 1 ] ] , dis [ y [ i - 1 ] ] );
        swap ( wrdis [ dis [ x [ i - 1 ] ] ] , wrdis [ dis [ y [ i - 1 ] ] ] );



        P [ i - 1 ] = -1 , Q [ i - 1 ] = -1;
        if ( s . size () )
        {

            int x = * s . begin () , z = wra [x];
            s . erase ( s . begin () );

            swap ( a [ wrdis [x] ] , a [z] );
            swap ( wra [ a [ wrdis [x] ] ] , wra [ a [z] ] );
            if ( a [z] == dis [z] ) s . erase ( s . lower_bound ( dis [z] ) );

            P [ i - 1 ] = wrdis [x] - 1 , Q [ i - 1 ] = z - 1;
            r ++;

        }

        if ( P [ i - 1 ] == -1 )
        {
            P [ i - 1 ] = 0;
            Q [ i - 1 ] = 0;
            r ++;
        }

    }
    return r;
}

Compilation message (stderr)

sorting.cpp: In function 'bool ck(int)':
sorting.cpp:50:17: warning: declaration of 'x' shadows a global declaration [-Wshadow]
   50 |             int x = * s . begin () , z = wra [x];
      |                 ^
sorting.cpp:5:36: note: shadowed declaration is here
    5 | int n , m , a [2003] , aa [2003] , x [20004] , y [20004] , dis [20004] , wrdis [20004] , wra [20004] , P [20004] , Q [20004];
      |                                    ^
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:61:73: warning: declaration of 'Q' shadows a global declaration [-Wshadow]
   61 | int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
      |                                                                     ~~~~^~~
sorting.cpp:5:116: note: shadowed declaration is here
    5 | int n , m , a [2003] , aa [2003] , x [20004] , y [20004] , dis [20004] , wrdis [20004] , wra [20004] , P [20004] , Q [20004];
      |                                                                                                                    ^
sorting.cpp:61:64: warning: declaration of 'P' shadows a global declaration [-Wshadow]
   61 | int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
      |                                                            ~~~~^~~
sorting.cpp:5:104: note: shadowed declaration is here
    5 | int n , m , a [2003] , aa [2003] , x [20004] , y [20004] , dis [20004] , wrdis [20004] , wra [20004] , P [20004] , Q [20004];
      |                                                                                                        ^
sorting.cpp:130:17: warning: declaration of 'x' shadows a global declaration [-Wshadow]
  130 |             int x = * s . begin () , z = wra [x];
      |                 ^
sorting.cpp:5:36: note: shadowed declaration is here
    5 | int n , m , a [2003] , aa [2003] , x [20004] , y [20004] , dis [20004] , wrdis [20004] , wra [20004] , P [20004] , Q [20004];
      |                                    ^

• Subtask 1: 8 / 8
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 18 / 18
• Subtask 5: 0 / 20
• Subtask 6: 0 / 26