Submission #689817

#	Time	Username	Problem	Language	Result	Execution time	Memory
689817		alexdd	DEL13 (info1cup18_del13)	C++17	100 / 100	50 ms	2584 KiB

del13

#include<bits/stdc++.h>
using namespace std;
#define int long long
int n,q;
int v[100005];
int gap[100005];
vector<int> sol;
vector<int> sol2;
signed main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);
    int t;
    cin>>t;
    while(t--)
    {
        sol.clear();
        sol2.clear();
        for(int i=0;i<100005;i++)
            gap[i]=0;
        cin>>n>>q;
        for(int i=1;i<=q;i++)
        {
            cin>>v[i];
            gap[i-1]=v[i]-v[i-1]-1;
        }
        if(q==0)
        {
            cout<<-1<<"\n";
            continue;
        }
        gap[q] = n - v[q];
        q++;
        v[q] = n+1;
        bool impossible=0;
        for(int i=1;i<q;i++)
        {
            if(impossible)
                break;
            if(gap[i-1]==0 || gap[i]==0)
                continue;
            if(gap[i-1]%2==1 && gap[i]>=1 && gap[i-1]>=1)///daca trebuie sa scad 1
            {
                sol.push_back(v[i]);
                gap[i]--;
                gap[i-1]--;
            }
        }
        for(int i=0;i<q;i++)
            if(gap[i]%2==1)
                impossible=1;

        int inc = 0;
        for(int i=0;i<=q;i++)
        {
            if(impossible)
                break;
            if(gap[i]==0)
            {
                if(inc!=i)
                {
                    if((i-inc)%2==0)
                    {
                        for(int j=inc;j<i;j+=2)
                        {
                            sol.push_back(v[j+1]);
                            sol.push_back(v[j+1]);
                            gap[j]-=2;
                            gap[j+1]-=2;
                        }
                    }
                    else
                    {
                        int mxm=0,unde=-1;
                        bool avem=0;
                        int unde_avem=-1;
                        for(int j=inc;j<i;j++)
                        {
                            if((j-inc)%2==0 && gap[j]!=v[j+1]-v[j]-1)
                            {
                                avem=1;
                                unde_avem=j;
                            }
                            if(j>inc && j<i-1 && gap[j]>=4 && (j-inc)%2==1)
                            {
                                mxm=gap[j];
                                unde=j;
                            }
                        }
                        if(avem)
                        {
                            int cate=0;
                            for(int j=inc;j<i;j++)
                            {
                                if(j!=unde_avem)
                                    cate++;
                                if(cate%2==1)
                                {
                                    sol.push_back(v[j+1]);
                                    sol.push_back(v[j+1]);
                                    gap[j]-=2;
                                    gap[j+1]-=2;
                                }
                            }
                        }
                        else
                        {
                            if(mxm<4)
                                impossible=1;
                            else
                            {
                                for(int j=unde;j<i;j+=2)
                                {
                                    sol.push_back(v[j+1]);
                                    sol.push_back(v[j+1]);
                                    gap[j]-=2;
                                    gap[j+1]-=2;
                                }
                                for(int j=inc;j<unde;j+=2)
                                {
                                    sol.push_back(v[j+1]);
                                    sol.push_back(v[j+1]);
                                    gap[j]-=2;
                                    gap[j+1]-=2;
                                }
                            }
                        }
                    }
                }
                inc=i+1;
            }
        }

        if(!impossible)
        {
            for(int i=0;i<q;i++)
            {
                if(gap[i]==0)
                    continue;
                if(gap[i]<0 || gap[i]%2==1 || gap[i]==v[i+1]-v[i]-1)
                {
                    impossible=1;
                    break;
                }
                int mij=(v[i+1]+v[i])/2;
                while(gap[i]>0)
                {
                    sol2.push_back(mij);
                    gap[i]-=2;
                }
            }
        }

        if(impossible)
        {
            cout<<-1<<"\n";
            continue;
        }
        cout<<sol.size() + sol2.size()<<"\n";
        for(int i=0;i<sol2.size();i++)
            cout<<sol2[i]<<" ";
        for(int i=0;i<sol.size();i++)
            cout<<sol[i]<<" ";
        cout<<"\n";
    }
    return 0;
}
/**
cazuri pe care nu merge solutia:
1
20 6
4 12 15 18 19 20
my solution: -1

*/

Compilation message (stderr)

del13.cpp: In function 'int main()':
del13.cpp:159:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  159 |         for(int i=0;i<sol2.size();i++)
      |                     ~^~~~~~~~~~~~
del13.cpp:161:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  161 |         for(int i=0;i<sol.size();i++)
      |                     ~^~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 15 / 15
• Subtask 3: 15 / 15
• Subtask 4: 25 / 25
• Subtask 5: 30 / 30