Submission #467819

#	Time	Username	Problem	Language	Result	Execution time	Memory
467819		blue	The Collection Game (BOI21_swaps)	C++17	100 / 100	6 ms	544 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)
{
    vector<int> a, b;

    for(int i = 0; i < A.size(); i++)
    {
        // cerr << "adding " << A[i] << ' ' << B[i] << '\n';
        if(0 <= A[i] && A[i] < N && 0 <= B[i] && B[i] < N)
        {
            // cerr << "added!\n";
            a.push_back(A[i]);
            b.push_back(B[i]);
        }
    }

    if(a.size() == 0) return;
    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);
    // }
    // cerr << "check\n";

    for(int p = 1; p < N; p *= 2)
    {
        for(int k = p; k >= 1; k /= 2)
        {
            vector<int> A, B;
            for(int j = k % p; j <= n-1-k; j += 2*k)
            {
                for(int i = 0; i <= k-1; i++)
                {
                    if((i+j)/(2*p) == (i+j+k)/(2*p))
                    {
                        // cerr << i+j << ' ' << i+j+k << '\n';
                        if(i+j+k < N)
                        {
                        A.push_back(i+j);
                        B.push_back(i+j+k);

                        }
                    }
                }
            }
            do_comparisons(A, B);
        }
    }

    answer(r);
}

Compilation message (stderr)

swaps.cpp: In function 'void do_comparisons(std::vector<int>, std::vector<int>)':
swaps.cpp:15:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |     for(int i = 0; i < A.size(); i++)
      |                    ~~^~~~~~~~~~
swaps.cpp:27:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     for(int i = 0; i < A.size(); i++)
      |                    ~~^~~~~~~~~~
swaps.cpp:34:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |     for(int i = 0; i < A.size(); i++)
      |                    ~~^~~~~~~~~~

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