Submission #1055382

#	Time	Username	Problem	Language	Result	Execution time	Memory
1055382		fryingduc	Index (COCI21_index)	C++17	110 / 110	672 ms	151700 KiB

index

/**
 *	author: fryingduc
 *	created:03.09.2023 20:39:40
**/
#include "bits/stdc++.h"
using namespace std;

#ifdef duc_debug
#include "bits/debug.h"
#else 
#define debug(...)     
#endif

/* #define int long long */

const int maxn = 2e5+5;
const int off = (1 << 18);
struct Node{
    int x;
    Node *l, *r;
    Node (int _x = 0, Node *_l = 0, Node *_r = 0){
        x = _x;
        l = _l;
        r = _r;
    }
};
Node* liu(){
    Node *x = new Node();
    x->r = x->l = x;
    return x;
}
Node *tmp;
Node *tree[maxn];
Node *update(Node *ind, int l, int r, int x){
    if(x < l || x > r) return ind;
    if(l == r){
        return new Node(ind->x + 1, liu(), liu()); 
    }
    int mid = (l + r) / 2;
    Node *left = update(ind->l, l, mid, x);
    Node *right = update(ind->r, mid + 1, r, x);
    return new Node(left->x + right->x, left, right);
}
int get(Node *ind, Node *prev, int l, int r, int x){
    if(x > r || l >= maxn) return 0;
    if(l >= x) return ind->x - prev->x;

    int mid = (l + r) / 2;
    return get(ind->l, prev->l, l, mid, x) + get(ind->r, prev->r, mid + 1, r, x);
}
int get(Node *ind, Node *prev, int x){
    return get(ind, prev, 1, off, x);
}
int n, q, a[maxn];
void solve(){
    cin >> n >> q;
    for(int i = 1; i <= n; ++i){
        cin >> a[i];
        tmp = liu();
        if(i > 1) tmp = tree[i - 1];
        tree[i] = update(tmp, 1, off, a[i]);
    }
    while(q--){
        int el, er; cin >> el >> er;
        int l = 0, r = maxn, res = 0;
        tmp = liu();
        if(el > 1) tmp = tree[el - 1];
        while(l <= r){
            int mid = (l + r) / 2;
            if(get(tree[er], tmp, mid) >= mid){
                l = mid + 1;
                res = mid;
            }
            else r = mid - 1;
        }
        cout << res << '\n';

    }
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int test = 1;
    /* cin >> test; */
    for(int i = 1; i <= test; i++){
        /* cout << "Case " << "#" << i << ": "; */
        solve();
    }

    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 50 / 50