Submission #519126

#	Time	Username	Problem	Language	Result	Execution time	Memory
519126		lucri	Cat (info1cup19_cat)	C++17	100 / 100	931 ms	12372 KiB

cat

    #include <iostream>
    using namespace std;
    int ans1[6000010],v[3000010],r,n,ans2[6000010],ans,poz[3000010];
    int main()
    {
        int t;
        cin>>t;
        ++t;
        while(--t)
        {
            int ver=0;
            cin>>n;
            for(int i=1;i<=n;++i)
            {
                cin>>v[i];
                poz[v[i]]=i;
            }
            n/=2;
            for(int i=1;i<=n;++i)
            {
                if(v[i]+v[2*n+1-i]!=2*n+1)
                {
                    ver=1;
                    break;
                }
                if(v[i]>n)
                    ++ver;
            }
            if(ver%2==1)
            {
                cout<<-1<<'\n';
                continue;
            }
            ans=0;
            ver=0;
            for(int i=1;i<=n;++i)
            {
                while(v[i]!=i&&v[i]!=n*2-i+1)
                {
                    ++ans;
                    ans1[ans]=v[i];
                    ans2[ans]=i;
                    swap(poz[v[i]],poz[v[v[i]]]);
                    swap(poz[v[2*n-i+1]],poz[v[2*n-v[i]+1]]);
                    swap(v[2*n-i+1],v[2*n-v[i]+1]);
                    swap(v[i],v[v[i]]);
                }
            }
            for(int i=1;i<=n;++i)
            {
                if(v[i]>n)
                {
                    if(ver==0)
                        ver=i;
                    else
                    {
                        ++ans;
                        ans1[ans]=ver;
                        ans2[ans]=2*n-i+1;
                        swap(v[i],v[2*n-ver+1]);
                        swap(v[ver],v[2*n-i+1]);
                        swap(poz[v[i]],poz[v[2*n-ver+1]]);
                        swap(poz[v[ver]],poz[v[2*n-i+1]]);
                        ++ans;
                        ans1[ans]=ver;
                        ans2[ans]=i;
                        swap(v[i],v[ver]);
                        swap(v[2*n-ver+1],v[2*n-i+1]);
                        swap(poz[v[i]],poz[v[ver]]);
                        swap(poz[v[2*n-ver+1]],poz[v[2*n-i+1]]);
                        ver=0;
                    }
                }
            }
            cout<<ans<<' '<<ans<<'\n';
            for(int i=1;i<=ans;++i)
                cout<<ans1[i]<<' '<<ans2[i]<<'\n';
        }
        return 0;
    }

• Subtask 1: 15 / 15
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 15 / 15
• Subtask 5: 35 / 35