Submission #636037

#	Time	Username	Problem	Language	Result	Execution time	Memory
636037		shafinalam	Sorting (IOI15_sorting)	C++14	20 / 100	1072 ms	596 KiB

sorting

#include "sorting.h"
#include<bits/stdc++.h>
using namespace std;
 
int n , m , a [200005] , aa [200005] , x [600005] , y [600005] , dis [200005] , wrdis [200005] , wra [200005];
 
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 > dq;
    for ( int i = 1 ; i <= n ; i ++ )
    {
        if ( dis [i] != a [i] ) dq . 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 ( dis [ x [ i - 1 ] ] , dis [ y [ i - 1 ] ] );
        swap ( wrdis [ dis [ x [ i - 1 ] ] ] , wrdis [ dis [ y [ i - 1 ] ] ] );
        swap ( wra [ a [ x [ i - 1 ] ] ] , wra [ a [ y [ i - 1 ] ] ] );
 
 
        int x = * dq . begin ();
        dq . erase ( dq . begin () );
 
        int j = wrdis [x];
 
        int y = wra [x];
 
        swap ( a [j] , a [y] );
        swap ( wra [ a [j] ] , wra [ a [y] ] );
 
        if ( dis [y] == a [y] ) dq . erase ( dq . lower_bound ( y ) );
    }
    if ( dq . size () == 0 ) return 1;
    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 , r = m + 1 , mid;
    while ( l < r )
    {
        mid = ( l + r ) / 2;
        if ( ck ( mid ) ) r = mid;
        else l = mid + 1;
    }
    m = l;
    int rr = 0;
    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 [ dis [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 > dq;
    for ( int i = 1 ; i <= n ; i ++ )
    {
        if ( dis [i] != a [i] ) dq . insert ( dis [i] );
    }
    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 rr;
        swap ( a [ x [ i - 1 ] ] , a [ y [ i - 1 ] ] );
        swap ( dis [ x [ i - 1 ] ] , dis [ y [ i - 1 ] ] );
        swap ( wrdis [ dis [ x [ i - 1 ] ] ] , wrdis [ dis [ y [ i - 1 ] ] ] );
        swap ( wra [ a [ x [ i - 1 ] ] ] , wra [ a [ y [ i - 1 ] ] ] );
 
 
        int x = * dq . begin ();
        dq . erase ( dq . begin () );
 
        int j = wrdis [x];
 
        int y = wra [x];
 
        swap ( a [j] , a [y] );
        swap ( wra [ a [j] ] , wra [ a [y] ] );
 
        P [ i - 1 ] = j - 1 , Q [ i - 1 ] = y - 1;
        rr ++;
 
        if ( dis [y] == a [y] ) dq . erase ( dq . lower_bound ( y ) );
    }
    return rr;
}

Compilation message (stderr)

sorting.cpp: In function 'bool ck(int)':
sorting.cpp:44:13: warning: declaration of 'x' shadows a global declaration [-Wshadow]
   44 |         int x = * dq . begin ();
      |             ^
sorting.cpp:5:40: note: shadowed declaration is here
    5 | int n , m , a [200005] , aa [200005] , x [600005] , y [600005] , dis [200005] , wrdis [200005] , wra [200005];
      |                                        ^
sorting.cpp:49:13: warning: declaration of 'y' shadows a global declaration [-Wshadow]
   49 |         int y = wra [x];
      |             ^
sorting.cpp:5:53: note: shadowed declaration is here
    5 | int n , m , a [200005] , aa [200005] , x [600005] , y [600005] , dis [200005] , wrdis [200005] , wra [200005];
      |                                                     ^
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:118:13: warning: declaration of 'x' shadows a global declaration [-Wshadow]
  118 |         int x = * dq . begin ();
      |             ^
sorting.cpp:5:40: note: shadowed declaration is here
    5 | int n , m , a [200005] , aa [200005] , x [600005] , y [600005] , dis [200005] , wrdis [200005] , wra [200005];
      |                                        ^
sorting.cpp:123:13: warning: declaration of 'y' shadows a global declaration [-Wshadow]
  123 |         int y = wra [x];
      |             ^
sorting.cpp:5:53: note: shadowed declaration is here
    5 | int n , m , a [200005] , aa [200005] , x [600005] , y [600005] , dis [200005] , wrdis [200005] , wra [200005];
      |                                                     ^

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