Submission #466420

#	Time	Username	Problem	Language	Result	Execution time	Memory
466420		daisy	Xor Sort (eJOI20_xorsort)	C++17	100 / 100	11 ms	1008 KiB

xorsort

#include<iostream>
#include<vector>
#include<algorithm>
#define endl '\n'
using namespace std;
int n,s,p[1005];
pair<int,int> m[1005];
vector< pair<int,int> > v;
bool cmp(pair<int,int> a, pair<int,int> b)
{
    return a.first>b.first;
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin>>n>>s;

    for(int i=1;i<=n;i++){
        cin>>m[i].first;
        m[i].second=i;
     }

    if(s==2){
    for(int i=1;i<=(1<<20);i*=2)
    {
        for(int j=1;j<n;j++)
        {
            if((i&m[j].first))
            {
                if(!(i&m[j+1].first))
                {
                    v.push_back({j+1,j});
                    m[j+1].first^=m[j].first;
                }

                    v.push_back({j,j+1});
                    m[j].first^=m[j+1].first;
            }
        }
    }
    }

    if(s==1){
    sort(m+1,m+n+1,cmp);
     int t;

    for(int i=1;i<=n;i++)
    {
        t=m[i].second-p[m[i].second];
        for(int j=m[i].second+1;j<=n;j++) p[j]++;

        for(int j=1;j<=min(n-1,n-i+1);j++)
        {
            v.push_back({j,j+1});
        }
        for(int j=t+1;j<=n-i+1;j++)
        {
            v.push_back({j,j-1});
        }
        for(int j=t-2;j>=1;j--)
        {
            v.push_back({j,j+1});
        }
    }
}

  cout<<v.size()<<endl;

   for(int i=0;i<v.size();i++)
   {
       cout<<v[i].first<<" "<<v[i].second<<endl;
   }

}

Compilation message (stderr)

xorsort.cpp: In function 'int main()':
xorsort.cpp:72:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |    for(int i=0;i<v.size();i++)
      |                ~^~~~~~~~~

• Subtask 1: 25 / 25
• Subtask 2: 35 / 35
• Subtask 3: 40 / 40