Submission #1154423

#	Time	Username	Problem	Language	Result	Execution time	Memory
1154423		yhkhoo	Index (COCI21_index)	C++20	110 / 110	2468 ms	48540 KiB

index

#include <bits/stdc++.h>
using namespace std;

typedef pair<int, int> pii;
#define fi first
#define se second

const int MAXN = 200005;
vector<int> t[4*MAXN];
int a[MAXN];

void build(int tx, int tl, int tr){
    // cerr << tl << ' ' << tr << '\n';
    if(tl == tr){
        t[tx] = {a[tl]};
        return;
    }
    int tm = (tl+tr)/2;
    build(tx*2, tl, tm); build(tx*2+1, tm+1, tr);
    merge(t[tx*2].begin(), t[tx*2].end(), t[tx*2+1].begin(), t[tx*2+1].end(), back_inserter(t[tx]));
}

int query(int tx, int tl, int tr, int l, int r, int x){
    if(r < tl || l > tr){
        return 0;
    }
    if(l == tl && r == tr){
        return t[tx].end() - lower_bound(t[tx].begin(), t[tx].end(), x);
    }
    int tm = (tl+tr)/2;
    return query(tx*2, tl, tm, l, min(r, tm), x) + query(tx*2+1, tm+1, tr, max(l, tm+1), r, x);
}

int main(){
    cin.tie(0); ios_base::sync_with_stdio(0);
    int n, q;
    cin >> n >> q;
    for(int i=1; i<=n; i++){
        cin >> a[i];
    }
    build(1, 1, n);
    while(q--){
        int l, r;
        cin >> l >> r;
        int bl=1, br=200000, bm;
        while(bl < br){
            // cerr << bl << ' ' << br << ' ' << bm << '\n';
            bm = (bl+br)/2;
            if(br-bl == 1){
                bm = br;
            }
            if(query(1, 1, n, l, r, bm) < bm){
                br = bm-1;
            }
            else{
                bl = bm;
            }
        }
        cout << bl << '\n';
    }
    return 0;
}

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