Submission #1292731

#	Time	Username	Problem	Language	Result	Execution time	Memory
1292731		M_SH_O	Alternating Heights (CCO22_day1problem1)	C++20	7 / 25	1096 ms	2724 KiB

Main

/*#pragma GCC optimize("O3")
#pragma GCC optimization("Ofast,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")*/
#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<pair<ll, ll>>
#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 ordered_set tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update>

using namespace std;
//using namespace __gnu_pbds;

const ll INF = 1e18+7;
const int lg = 20;
const ll MOD = 1e9+7;
//const ll MOD2 = 998244353;
//const ll MOD3 = 1e6+3;

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

vvll g;
vbool us, us1;
bool q1;

void dfs(ll v) {
    us[v] = 1;
    us1[v] = 1;
    for (int i : g[v]) {
        if (us1[i]) q1 = 1;
        if (!us[i]) dfs(i);
    }
    us1[v] = 0;
}

int main() {
    speed;

    ll n, k, q;
    cin >> n >> k >> q;
    vll a(n);
    for (int i = 0; i < n; i ++) {
        cin >> a[i];
    }

    while (q --) {
        ll l, r;
        cin >> l >> r;
        l --, r --;
        g.clear();
        us.clear();
        us1.clear();
        g.resize(k+7);
        us.resize(k+7, 0);
        us1.resize(k+7, 0);

        for (int i = l; i < r; i ++) {
            if ((i-l) % 2 == 0) g[a[i]].pb(a[i+1]);
            else g[a[i+1]].pb(a[i]);
        }
        q1 = 0;

        for (int i = 1; i <= k; i ++) {
            if (!us[i]) dfs(i);
        }

        if (!q1) cout << "YES" << endl;
        else cout << "NO" << endl;
    }
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 6
• Subtask 3: 7 / 7
• Subtask 4: 0 / 8