Submission #975051

#	Time	Username	Problem	Language	Result	Execution time	Memory
975051		LucaIlie	Packing Biscuits (IOI20_biscuits)	C++17	9 / 100	1067 ms	860 KiB

biscuits

#include "biscuits.h"
#include <bits/stdc++.h>

using namespace std;

const int k = 60;
long long x;
long long biscuits[k];
long long sum[k][k], mask[k][k];
int ind[k][k];
long long solutions;
vector<int> sol;

void countSolutions( int b, long long s ) {
    solutions++;

    //for ( int i: sol )
       // printf( "%d ", i );
    //printf( "\n" );

    s >>= 1;
    for ( int j = b; j < k; j++ ) {
        int i = ind[b][j];
        long long cs = ((s + mask[b][i]) >> (i - b)) + sum[b][i];
      //  printf( "%d %d %d\n", b, i, cs );
        if ( cs >= x )
            countSolutions( i + 1, cs - x );
        else
            break;
    }
}

int p;
bool cmp( int p1, int p2 ) {
    //long long r1 = ((mask[p][p1] >> (p1 - p)) + sum[p][p1] - x) >> p2, r2 = ((mask[p][p2] >> (p2 - p)) + sum[p][p2] - x) >> p1;
    return ((__int128)mask[p][p1] << p) + (((__int128)sum[p][p1] - x) << p1) > ((__int128)mask[p][p2] << p) + (((__int128)sum[p][p2] - x) << p2);
}

long long count_tastiness( long long X, vector <long long> a ) {
    long long s;

    x = X;
    a.resize( k );

    s = 0;
    for ( int b = 0; b < k; b++ ) {
        a[b] += s;
        if ( a[b] > x ) {
            s = a[b] - x;
            a[b] = x + s % 2;
            s /= 2;
        } else
            s = 0;
        biscuits[b] = a[b];
    }

    for ( int i = 0; i < k; i++ ) {
        sum[i][i] = biscuits[i];
        for ( int j = i + 1; j < k; j++ ) {
            mask[i][j] = mask[i][j - 1] + (((long long)sum[i][j - 1] % 2) << (j - i - 1));
            sum[i][j] = sum[i][j - 1] / 2 + biscuits[j];
            //printf( "%d %d: %d %d\n", i, j, sum[i][j], mask[i][j] );
        }
    }
    for ( int b = 0; b < k; b++ ) {
        for ( int i = b; i < k; i++ )
            ind[b][i] = i;
        p = b;
        sort( ind[b] + b, ind[b] + k, cmp );
    }

    solutions = 0;
    countSolutions( 0, 0 );

    return solutions;
}

• Subtask 1: 9 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 21
• Subtask 4: 0 / 35
• Subtask 5: 0 / 23