Submission #444415

#	Time	Username	Problem	Language	Result	Execution time	Memory
444415		blue	The Collection Game (BOI21_swaps)	C++17	0 / 100	1 ms	200 KiB

swaps

#include "swaps.h"
#include <vector>
#include <iostream>
using namespace std;

int N;
int V;

vector<int> r;

void do_comparisons(vector<int> A, vector<int> B)
{
    for(int i = 0; i < A.size(); i++)
    {
        schedule(r[ A[i] ], r[ B[i] ]);
    }

    vector<int> C = visit();

    for(int i = 0; i < A.size(); i++)
    {
        if(C[i] == 0)
            swap(r[ A[i] ], r[ B[i] ]);
    }
}


void solve(int n, int v)
{
    N = n;
    V = v;
    r = vector<int>(N);
    for(int i = 1; i <= N; i++) r[i - 1] = i;


    // for(int v = 1; v <= min(V, N); v++)
    // {
    //     vector<int> A, B;
    //     if(v % 2 == 0)
    //     {
    //         for(int i = 0; i+1 < N; i += 2)
    //         {
    //             A.push_back(i);
    //             B.push_back(i+1);
    //         }
    //     }
    //     else
    //     {
    //         for(int i = 1; i+1 < N; i += 2)
    //         {
    //             A.push_back(i);
    //             B.push_back(i+1);
    //         }
    //     }
    //
    //     do_comparisons(A, B);
    // }

    for(int X = 2; X <= N; X *= 2)
    {
        // cerr << "X = " << X << '\n';
        int p = 0, q = X-1;
        vector<int> A, B;
        while(p < N)
        {
            for(int i = 0; i < X/2; i++)
            {
                if(p + i < N && 0 <= q - i && q - i < N)
                {
                    A.push_back(p + i);
                    B.push_back(q - i);
                }
            }

            p += X;
            q += X;
        }

        do_comparisons(A, B);
        A.clear();
        B.clear();




        for(int Y = X/2; Y >= 2; Y /= 2)
        {
            for(int i = 0; i + Y/2 < N; i++)
            {
                if((i / (Y/2)) % 2 == 0)
                {
                    A.push_back(i);
                    B.push_back(i + Y/2);
                }
            }
            do_comparisons(A, B);
            A.clear();
            B.clear();
        }
    }

    answer(r);
}

Compilation message (stderr)

swaps.cpp: In function 'void do_comparisons(std::vector<int>, std::vector<int>)':
swaps.cpp:13:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |     for(int i = 0; i < A.size(); i++)
      |                    ~~^~~~~~~~~~
swaps.cpp:20:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     for(int i = 0; i < A.size(); i++)
      |                    ~~^~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 3
• Subtask 4: 0 / 2
• Subtask 5: 0 / 9
• Subtask 6: 0 / 6
• Subtask 7: 0 / 9
• Subtask 8: 0 / 6
• Subtask 9: 0 / 21
• Subtask 10: 0 / 14
• Subtask 11: 0 / 9
• Subtask 12: 0 / 6