Submission #1209744

#	Time	Username	Problem	Language	Result	Execution time	Memory
1209744		M_SH_O	DEL13 (info1cup18_del13)	C++20	0 / 100	1096 ms	320 KiB

del13

#include <bits/stdc++.h>
/*#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>*/

#define ll long long
#define ll1 long long
#define ull unsigned long long
#define dou long double
#define str string
#define vll vector<ll>
#define vi vector<int>
#define pll pair<ll, ll>
#define vpll vector<pll>
#define vbool vector<bool>
#define vstr vector<str>
#define vvll vector<vll>
#define pb push_back
#define pf push_front
#define endl "\n"
#define fr first
#define se second
// #define sortcmp(a) sort(a.begin(), a.end(), cmp)
#define sort(a) sort(a.begin(), a.end())
#define reverse(a) reverse(a.begin(), a.end())
#define speed ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define INF 5000000000000000000
#define ordered_set tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update>

using namespace std;
//using namespace __gnu_pbds;

mt19937 rng(1488);
ll randll(ll l, ll r){
    return uniform_int_distribution<ll>(l, r)(rng);
}

int main() {
    speed;
    srand(time(0));

    ll t;
    cin >> t;

    while (t --) {
        ll n, k;
        cin >> n >> k;
        vll a;
        a.pb(0);
        vll b1;
        for (int i = 0; i < k; i ++) {
            ll b;
            cin >> b;
            b1.pb(b);
            a.pb(b);
        }
        a.pb(n+1);
        vll b;
        for (int i = 1; i < a.size(); i ++) {
            b.pb(a[i]-a[i-1]-1);
            //cout << a[i]-a[i-1]-1 << ' ';
        }
        //cout << endl;

        vll res1;

        ll cnt = 0;
        for (int i = 0; i < b.size(); i ++) {
            if (b[i] % 2) cnt ++;
            else {
                if (cnt % 2 == 1) {
                    ll x = -1;
                    for (int j = i+1; j < b.size(); j ++) {
                        if (b[j] % 2) {
                            x = j;
                            break;
                        }
                    }
                    if (x != -1) {
                        while (x > i) {
                            res1.pb(a[x]);
                            b[x] --;
                            b[x-1] --;
                            x --;
                        }
                    }
                }
                cnt = 0;
            }
        }
        /*for (int i = 0; i < b.size(); i ++) {
            cout << b[i] << ' ';
        }
        cout << endl;*/

        vbool dp[2];
        dp[0].resize(n, 0);
        dp[1].resize(n, 0);
        dp[0][0] = 1;
        if (b[0] == 0) {
            dp[0][0] = 0;
            dp[1][0] = 1;
        }


        for (int i = 1; i < b.size(); i ++) {
            if (b[i] == 0) {
                if (dp[1][i-1]) dp[1][i] = 1;
                //cout << dp[0][i] << ' ' << dp[1][i] << endl;
                continue;
            }
            if (dp[0][i-1]) {
                if (b[i-1] % 2 == 1 && b[i] % 2 == 1) {
                    dp[1][i] = 1;
                }
                if (b[i-1] % 2 == 0) {
                    if (b[i] % 2 == 1 && b[i] > 1) dp[0][i] = 1;
                    if (b[i] % 2 == 0) dp[1][i] = 1;
                }
            }
            if (dp[1][i-1]){
                dp[0][i] = 1;
                if (b[i] % 2 == 0 && b[i-1] > 2) dp[1][i] = 1;
            }
            //cout << dp[0][i] << ' ' << dp[1][i] << endl;
        }

        if (!dp[1][b.size()-1]) {
            //while (1);
            cout << -1 << endl;
            continue;
        }

        ll k1 = 1;
        vll res;
        vll c = b;

        for (int i = b.size()-1; i > 0; i --) {
            if (b[i] == 0) continue;
            if (dp[0][i-1]) {
                if (b[i-1] % 2 == 1 && b[i] % 2 == 1 && k1) {
                    c[i] --;
                    c[i-1] --;
                    res.pb(a[i]);

                    k1 = 0;
                    continue;
                }
                if (b[i-1] % 2 == 0) {
                    if (b[i] % 2 == 1 && b[i] > 1 && !k1) {
                        c[i] -= 2;
                        c[i-1] -= 2;
                        res.pb(a[i]);
                        res.pb(a[i]);
                        continue;
                    }
                    if (b[i] % 2 == 0 && k1) {
                        c[i] -= 2;
                        c[i-1] -= 2;
                        res.pb(a[i]);
                        res.pb(a[i]);
                        k1 = 0;
                        continue;
                    }
                }
            }
            if (dp[1][i-1]){
                if (!k1) {
                    k1 = 1;
                    continue;
                }
                if (b[i] % 2 == 0 && b[i-1] > 2 && k1) {
                    c[i] -= 2;
                    c[i-1] -= 2;
                    res.pb(a[i]);
                    res.pb(a[i]);
                    k1 = 1;
                }
            }
        }
        vll res2;
        for (int i = 0; i < c.size(); i ++) {
            if (c[i] % 2) while (1);
            for (int j = 0; j < c[i]/2; j ++) {
                res2.pb((a[i]+a[i+1])/2);
            }
        }
        for (int i : res1) {
            res2.pb(i);
        }
        for (int i : res) {
            res2.pb(i);
        }
        res = res2;

        //reverse(res);

        vll d;
        for (int i = 1; i <= n; i ++) {
            d.pb(i);
        }
        bool q = 1;

        for (int i : res) {
            for (int j = 0; j < d.size(); j ++) {
                if (d[j] == i) {
                    if (j == 0 || j == d.size()-1) {
                        q = 0;
                        break;
                    }
                    d.erase(d.begin()+j+1);
                    d.erase(d.begin()+j-1);
                }

            }

            if (!q) break;
        }

        if (d != b1) q = 0;
        if (!q) {

            /*cout << "!!!!!!" << endl;
            cout << n << ' ' << k << endl;

            for (int i = 0; i < k; i ++) {
                cout << b1[i] << ' ';
            }
            cout << endl;
            return 0;*/
            while (1);
        }

        cout << res.size() << endl;
        for (int i : res) {
            cout << i << ' ';
        }

        cout << endl;
    }


}

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