Submission #971571

#	Time	Username	Problem	Language	Result	Execution time	Memory
971571		Cookie	Alternating Heights (CCO22_day1problem1)	C++14	25 / 25	260 ms	30696 KiB

Main

#include<bits/stdc++.h>
#include<fstream>
using namespace std;
#define sz(a) (int)a.size()
#define ALL(v) v.begin(), v.end()
#define ALLR(v) v.rbegin(), v.rend()
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
#define mpp make_pair
const ld PI = 3.14159265359, prec = 1e-9;;
//using u128 = __uint128_t;
//const int x[4] = {1, 0, -1, 0};
//const int y[4] = {0, -1, 0, 1};
const ll mod =1e9 + 7, pr = 31;
const int mxn = 5e5 + 5, mxq = 1e5 + 5, sq = 500, mxv = 5e4 + 1;
//const int base = (1 <<18);
const ll inf = 1e13 + 5, neg = -69420, inf2 = 1e14;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
// have fun!
int n, k, q;
int a[mxn + 1], nxt[mxn + 1], c[mxn + 1];
vt<pii>adj[mxn + 1];
bool cyc;
void dfs(int s, int l, int r){
    c[s] = 1;
    for(auto [v, id]: adj[s]){
        if(id < l || id >= r)continue;
        if(c[v] == 1)cyc = 1;
        else if(c[v] == 0){
            dfs(v, l, r);
        }
    }
    c[s] = 2;
}
bool check(int l, int r){
    for(int i = 1; i <= n; i++){
        c[i] = 0;
    }
    cyc = 0;
    for(int i = 1; i <= n; i++){
        if(!c[i])dfs(i, l, r);
    }
    return(!cyc);
}
void solve(){
    cin >> n >> k >> q;
    for(int i = 1; i <= n; i++)cin >> a[i];
    for(int i = 1; i < n; i++){
        if(i & 1)adj[a[i]].pb(mpp(a[i + 1], i));
        else adj[a[i + 1]].pb(mpp(a[i], i));
    }
    int r = 1;
    for(int i = 1; i <= n; i++){
        while(r < n && check(i, r + 1))r++;
        nxt[i] = r;
    }
    while(q--){
        int l, r; cin >> l >> r;
        cout << ((nxt[l] >= r) ? "YES" : "NO") << "\n";
    }
}



signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    //freopen("THREE.inp", "r", stdin);
    //freopen("THREE.out", "w", stdout);
    int tt; tt = 1;
    while(tt--){
        solve();

    }
    return(0);
}

Compilation message (stderr)

Main.cpp: In function 'void dfs(int, int, int)':
Main.cpp:35:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   35 |     for(auto [v, id]: adj[s]){
      |              ^

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