Submission #1174617

#	Time	Username	Problem	Language	Result	Execution time	Memory
1174617		guagua0407	DEL13 (info1cup18_del13)	C++20	0 / 100	1 ms	576 KiB

del13

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

void solve(){
    int n,q;
    cin>>n>>q;
    vector<int> a(q+2);
    a[0]=0;
    a[q+1]=n+1;
    for(int i=1;i<=q;i++){
        cin>>a[i];
    }
    vector<int> b;
    for(int i=1;i<=q+1;i++){
        b.push_back(a[i]-a[i-1]-1);
    }
    /*for(auto v:b){
        cout<<v<<' ';
    }
    cout<<'\n';*/
    vector<int> nxt(n+1),prv(n+1);
    for(int i=0;i<=n;i++){
        nxt[i]=i+1;
        prv[i]=i-1;
    }
    auto get=[&](int x,int d){
        for(int i=0;i<d;i++){
            x=nxt[x];
        }
        return x;
    };
    auto op=[&](int x){
        int a=prv[x];
        int b=nxt[x];
        nxt[a]=b;
        prv[b]=a;
    };
    auto del=[&](int x){
        op(prv[x]);
        op(nxt[x]);
    };
    vector<pair<int,int>> res;
    bool used=false;
    for(int i=0;i<(int)b.size();i++){
        if(b[i]==0){
            used=false;
            continue;
        }
        while(b[i]>2){
            res.push_back({0,a[i]});
            b[i]-=2;
        }
        if(i+1<(int)b.size() and b[i+1]>=b[i]){
            for(int j=0;j<b[i];j++){
                res.push_back({1,a[i+1]});
            }
            b[i+1]-=b[i];
            used=true;
            continue;
        }
        else{
            if(b[i]==2 and used){
                res.push_back({0,a[i]});
                used=false;
                continue;
            }
            else{
                cout<<-1<<'\n';
                return;
            }
        }
    }
    sort(all(res));
    cout<<(int)res.size()<<'\n';
    for(auto v:res){
        if(v.f==0){
            int x=get(v.s,2);
            cout<<x<<' ';
            del(x);
        }
        else{
            cout<<v.s<<' ';
            del(v.s);
        }
    }
    cout<<'\n';
    return;
}

int main() {_
    int t;
    cin>>t;
    while(t--){
        solve();
    }
    return 0;
}
//maybe its multiset not set
//yeeorz
//diaoborz

Compilation message (stderr)

del13.cpp: In function 'void setIO(std::string)':
del13.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
del13.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 15
• Subtask 3: 0 / 15
• Subtask 4: 0 / 25
• Subtask 5: 0 / 30