Submission #944134

#	Time	Username	Problem	Language	Result	Execution time	Memory
944134		LucaIlie	Uplifting Excursion (BOI22_vault)	C++17	100 / 100	3002 ms	3496 KiB

vault

#include <bits/stdc++.h>

using namespace std;

const int MAX_M = 300;
int MAX_S;
int MIN_S;
const long long INF = 1e18;
int m;
unordered_map<int, long long> taken, untaken;
long long dpCrt[2 * MAX_M * MAX_M + 1], dpPrv[2 * MAX_M * MAX_M + 1];

void add( int x, int k ) {
    swap( dpCrt, dpPrv );

    if ( x > 0 ) {
        for ( int r = 0; r < x; r++ ) {
            deque<pair<int, int>> d;
            for ( int i = 0, s = MIN_S + r; s <= MAX_S; i++, s += x ) {
                if ( !d.empty() && i - d.front().second > k )
                    d.pop_front();
                while ( !d.empty() && dpPrv[s - MIN_S] - i >= dpPrv[d.back().first - MIN_S] - d.back().second )
                    d.pop_back();
                d.push_back( { s, i } );
                dpCrt[s - MIN_S] = dpPrv[d.front().first - MIN_S] + i - d.front().second;
            }
        }
    } else {
        x = -x;
        for ( int r = 0; r < x; r++ ) {
            deque<pair<int, int>> d;
            for ( int i = 0, s = MAX_S - r; s >= MIN_S; i++, s -= x ) {
                if ( !d.empty() && i - d.front().second > k )
                    d.pop_front();
                while ( !d.empty() && dpPrv[s - MIN_S] - i >= dpPrv[d.back().first - MIN_S] - d.back().second )
                    d.pop_back();
                d.push_back( { s, i } );
                dpCrt[s - MIN_S] = dpPrv[d.front().first - MIN_S] + i - d.front().second;
            }
        }
    }

    for ( int s = MIN_S; s <= MAX_S; s++ )
        dpCrt[s - MIN_S] = (dpCrt[s - MIN_S] <= -INF + m ? -INF : dpCrt[s - MIN_S]);
}

void substract( int x, int k ) {
    swap( dpCrt, dpPrv );

    if ( x < 0 ) {
        x = -x;
        for ( int r = 0; r < x; r++ ) {
            deque<pair<int, int>> d;
            for ( int i = 0, s = MIN_S + r; s <= MAX_S; i++, s += x ) {
                if ( !d.empty() && i - d.front().second > k )
                    d.pop_front();
                while ( !d.empty() && dpPrv[s - MIN_S] + i >= dpPrv[d.back().first - MIN_S] + d.back().second )
                    d.pop_back();
                d.push_back( { s, i } );
                dpCrt[s - MIN_S] = dpPrv[d.front().first - MIN_S] - i + d.front().second;
            }
        }
    } else {
        for ( int r = 0; r < x; r++ ) {
            deque<pair<int, int>> d;
            for ( int i = 0, s = MAX_S - r; s >= MIN_S; i++, s -= x ) {
                if ( !d.empty() && i - d.front().second > k )
                    d.pop_front();
                while ( !d.empty() && dpPrv[s - MIN_S] + i >= dpPrv[d.back().first - MIN_S] + d.back().second )
                    d.pop_back();
                d.push_back( { s, i } );
                dpCrt[s - MIN_S] = dpPrv[d.front().first - MIN_S] - i + d.front().second;
            }
        }
    }

    for ( int s = MIN_S; s <= MAX_S; s++ )
        dpCrt[s - MIN_S] = (dpCrt[s - MIN_S] <= -INF + m ? -INF : dpCrt[s - MIN_S]);
}



int main() {
    long long l, u = 0, t = 0;

    cin >> m >> l;
    MIN_S = -m * m;
    MAX_S = m * m;
    for ( int i = -m; i <= m; i++ ) {
        cin >> untaken[i];
        u += untaken[i];
    }

    if ( l < 0 ) {
        for ( int i = 1; i <= m; i++ )
            swap( untaken[i], untaken[-i] );
        l = -l;
    }

    long long s = 0;
    for ( int i = -m; i <= 0; i++ ) {
        long long x = untaken[i];
        s += i * x;
        taken[i] += x;
        untaken[i] -= x;
        t += x;
        u -= x;
    }
    for ( int i = 1; i <= m; i++ ) {
        long long x = min( untaken[i], (l - s) / i );
        s += i * x;
        taken[i] += x;
        untaken[i] -= x;
        t += x;
        u -= x;
    }

    if ( s + m < l ) {
        for ( int i = -m; i < 0; i++ ) {
            long long x = min( taken[i], (l - s) / (-i) );
            s -= i * x;
            taken[i] -= x;
            untaken[i] += x;
            t -= x;
            u += x;
        }
    }

    /*cout << s << "\n";
    for ( int i = -m; i <= m; i++ )
        cout << i << " " << taken[i] << " " << untaken[i] << "\n";*/

    for ( int s = MIN_S; s <= MAX_S; s++ )
        dpCrt[s - MIN_S] = -INF;
    dpCrt[0 - MIN_S] = 0;

    for ( int i = -m; i <= m; i++ ) {
        add( i, min( (long long)m, untaken[i] ) );
        substract( i, min( (long long)m, taken[i] ) );
    }


    if ( l - s > MAX_S || dpCrt[l - s - MIN_S] == -INF )
        cout << "impossible\n";
    else
        cout << t + dpCrt[l - s - MIN_S] << "\n";

    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3-1: 10 / 10
• Subtask 3-2: 10 / 10
• Subtask 4-1: 10 / 10
• Subtask 4-2: 10 / 10
• Subtask 5-1: 10 / 10
• Subtask 5-2: 10 / 10
• Subtask 6-1: 10 / 10
• Subtask 6-2: 10 / 10