Submission #1288704

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288704		monaxia	Abracadabra (CEOI22_abracadabra)	C++20	0 / 100	6 ms	2360 KiB

Main

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

// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define pb push_back
#define ppb pop_back
#define fr first
#define sc second
#define all(v) v.begin(), v.end()
#define vektor vector

using namespace std;
using namespace __gnu_pbds; 

using ll = long long;
using ull = unsigned long long;
using ld = long double;

constexpr ull Mod = (119 << 23) | 1;
constexpr ull sqr = 223;
constexpr ld eps = 1e-9;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
long long random_ll(long long l, long long r) {if (l > r) return -1; return uniform_int_distribution<long long>(l, r)(rng);}

int n;
int a[100005];

pair <int, int> s[100005];

int bit[100005], nex[100005];

void update(int i, int val){
    for(; i <= 1e5; i += i & -i) bit[i] += val;
}

int query(int i){
    int ans = 0;
    for(; i >= 1; i -= i & -i) ans += bit[i];

    return ans;
}

set <pair <int, pair <int, int>>> ss;

void parti(int l, int r){
    int cur = a[l];
    
    while(l <= r){
        int xx = min(r, nex[l]);
        if(xx == -1) xx = r;

        ss.insert({a[l], {l, xx}});

        s[a[l]] = {l, xx};
        update(a[l], xx - l + 1);
        l = xx + 1;

    }
}

void solve(){

    memset(bit, 0, sizeof(bit));
    int m;
    cin >> n >> m;

    for(int i = 1; i <= n; i ++){
        cin >> a[i];
        nex[i] = - 1;
    }

    return;
    

    int cur = a[1];

    stack <int> stt;

    for(int i = 1; i <= n; i ++){
        while(!stt.empty() && a[stt.top()] < a[i]){
            nex[stt.top()] = i - 1;
            stt.pop();
        }

        stt.push(i);
    }
    
    parti(1, n);

    vector <pair <int, int>> q[n + 1];

    int ww = 0;

    for(int i = 1; i <= m; i ++){
        int t, j;
        cin >> t >> j;

        q[min(t, n)].pb({j, i}); 
        ww = t;
    }

    int res[m + 1];

    for(int _ = 0; _ <= n; _ ++){  
        for(auto& x : q[_]){
            int l = 1, r = n, ans = 1;

            while(l <= r){
                int mid = (l + r) >> 1;

                if(query(mid) >= x.fr) ans = mid, r = mid - 1;
                else l = mid + 1;
            }

            res[x.sc] = a[s[ans].fr + (x.fr - query(ans - 1) - 1)];
        }

        int l = 1, r = n, ans = n;

        while(l <= r){
            int mid = (l + r) >> 1;

            int as = query(mid);

            if(as == (n >> 1)){
                ans = mid;
                break;
            }

            if(as > (n >> 1)) r = mid - 1, ans = mid;
            else l = mid + 1;
        }

        if(query(ans) != n / 2){
            l = s[ans].fr, r = s[ans].sc;
            s[ans] = {0, 0};

            ss.erase({a[l], {l, r}});

            update(ans, - (r - l + 1));
                
            int prev = query(ans);

            parti(l, l + n / 2 - prev - 1);
            parti(l + n / 2 - prev, r);
        }

        
        // cout << l << "->" << l + n / 2 - prev - 1 << " " << l + n / 2 - prev  << "->" << r << ": \n";

        // for(auto& x : ss) cout << x.sc.fr << "->" << x.sc.sc << " "; cout << "\n";
    }

    for(int i = 1; i <= m; i ++) cout << res[i] << "\n";
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); 

    if(fopen("TREE.inp", "r")){
        freopen("TREE.inp", "r", stdin);
        freopen("TREE.out", "w", stdout);
    }

    int t = 1;

    // cin >> t;

    while(t --){
        solve();
        // cout << "\n";
    }

    cerr << "Code time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
    return 0;
}

// Whose eyes are those eyes?

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:164:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  164 |         freopen("TREE.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:165:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  165 |         freopen("TREE.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 40
• Subtask 3: 0 / 25
• Subtask 4: 0 / 25