제출 #955201

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
955201		shezitt	Index (COCI21_index)	C++14	110 / 110	1596 ms	136320 KiB

index

#include <iostream>
#include <algorithm>
#include <vector>
#include <cassert>
 
using namespace std;
 
using ll = long long;
#define int ll
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define raya cerr << "==================" << endl;
 
#define fore(i, a, b) for(int i=a; i<b; ++i)
 
const int N = 2e5+5;
 
int p[N], n, q;
 
int mp[N];
 
struct Node {
    Node *left, *right;
    int val;
 
    Node() {
        left = nullptr;
        right = nullptr;
        val = 0;
    }
 
};
 
int arr[N];
 
Node* version[N];
 
void init(Node *cur, int tl, int tr){
    if(tl == tr){
        cur->val = arr[tl];
        return;
    }
 
    int tm = (tl + tr) / 2;
 
    cur->left = new Node();
    cur->right = new Node();
 
    init(cur->left, tl, tm);
    init(cur->right, tm+1, tr);
 
    cur->val = cur->left->val + cur->right->val;
 
}
 
void update(Node *cur, Node *prev, int tl, int tr, int idx, int val){
    if(tl == tr){
        arr[tl] = val;
        cur->val = val;
        return;
    }
 
    int tm = (tl + tr) / 2;
 
    if(idx <= tm){
        cur->left = new Node();
        cur->right = prev->right;
        update(cur->left, prev->left, tl, tm, idx, val);
    } else {
        cur->left = prev->left;
        cur->right = new Node();
        update(cur->right, prev->right, tm+1, tr, idx, val);
    }
 
    cur->val = cur->left->val + cur->right->val;
 
}
 
void update(Node *cur, Node *prev, int idx, int val){
    update(cur, prev, 0, N-1, idx, val);
}
 
int query(Node *cur, int tl, int tr, int l, int r){
    if(l <= tl && tr <= r){
        return cur->val;
    }
 
    if(r < tl or tr < l){
        return 0;
    }
 
    int tm = (tl + tr) / 2;
 
    int p1 = query(cur->left, tl, tm, l, r);
    int p2 = query(cur->right, tm+1, tr, l, r);
 
    return p1 + p2;
 
}
 
int query(Node *cur, int l, int r){
    return query(cur, 0, N-1, l, r);
}
 
signed main(){
    cin >> n >> q;
 
    fore(i, 0, n){
        cin >> p[i];
    }
 
    version[0] = new Node();
    init(version[0], 0, N);
 
    fore(i, 0, n){
        version[i+1] = new Node();
        int prevVal = query(version[i], p[i], p[i]);
        update(version[i+1], version[i], p[i], prevVal + 1);
    }
 
    fore(i, 0, q){
        int l, r;
        cin >> l >> r;
 
        int low = 1, high = N;
        int res = -1;
 
        while(low <= high){
            int mid = low + (high - low) / 2;
 
            int cnt = query(version[r], mid, N-1) - query(version[l-1], mid, N-1);
 
            if(cnt >= mid){
                res = mid;
                low = mid+1;
            } else {
                high = mid-1;
            }
 
        }
 
        cout << res << endl;
 
    }
 
}

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