Submission #933202

#	Time	Username	Problem	Language	Result	Execution time	Memory
933202		LucaIlie	Swap (BOI16_swap)	C++17	100 / 100	172 ms	49752 KiB

swap

#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 2e5;
int v[2 * MAX_N + 2];
unordered_map<int, int> dp[MAX_N + 1];

int DP( int i, int x ) {
    if ( dp[i][x] != 0 )
        return dp[i][x];

    if ( x < v[2 * i] && x < v[2 * i + 1] )
        dp[i][x] = i;
    else if ( v[2 * i] < v[2 * i + 1] )
        dp[i][x] = DP( 2 * i, x );
    else {
        if ( x < v[2 * i] )  {
            DP( 2 *  i, x );
            DP( 2 * i + 1, x );
            if ( dp[2 * i][x] < dp[2 * i + 1][x] )
                dp[i][x] = DP( 2 * i, x );
            else
                dp[i][x] = DP( 2 * i + 1, x );
        }
        else {
            DP( 2 * i, v[2 * i] );
            DP( 2 * i + 1, v[2 * i] );
            if ( dp[2 * i][v[2 * i]] < dp[2 * i + 1][v[2 * i]] )
                dp[i][x] = DP( 2 * i + 1, x );
            else
                dp[i][x] = DP( 2 * i, x );
        }
    }

    return dp[i][x];
}

int main() {
    int n;

    cin >> n;
    for ( int i = 1; i <= n; i++ )
        cin >> v[i];
    for ( int i = n + 1; i <= 2 * n + 1; i++ )
        v[i] = n + 1;

    for ( int i = 1; 2 * i + 1 <= n; i++ ) {
        if (  v[2 * i] < v[i] && v[2 * i] < v[2 * i + 1] )
            swap( v[i], v[2 * i] );
        else if ( v[2 * i + 1] < v[i] && v[2 * i + 1] < v[2 * i] ) {
            swap( v[i], v[2 * i + 1] );

            if ( v[2 * i] < v[2 * i + 1] ) {
                if ( DP( 2 * i, v[2 * i] ) > DP( 2 * i + 1, v[2 * i] ) )
                    swap( v[2 * i], v[2 * i + 1] );
            } else {
                if ( DP( 2 * i, v[2 * i + 1] ) < DP( 2 * i + 1, v[2 * i + 1] ) )
                    swap( v[2 * i], v[2 * i + 1] );
            }
        }
    }
    if ( v[n / 2] > v[n] )
        swap( v[n / 2], v[n] );

    for ( int i = 1; i <= n; i++ )
        cout << v[i] << " ";

    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 11 / 11
• Subtask 3: 27 / 27
• Subtask 4: 20 / 20
• Subtask 5: 32 / 32