Kyselyt

#include <bits/stdc++.h>

#define N (1<<18)

using namespace std;

int v[N];
map<int, vector<int>> mp;

int main() {
    srand(time(0));
    int n, q;
    cin>>n>>q;
    for (int i = 1; i <= n; i++) {
        cin>>v[i];
        mp[v[i]].push_back(i);
    }
    for (int i = 1; i <= n; i++) {
        if (mp[v[i]].back() != n + 1) mp[v[i]].push_back(n + 1);
    }
    while (q --> 0) {
        int l, r;
        cin>>l>>r;
        for (int t = 0; t < 20; t++) {
            int len = r - l + 1;
            int i = l + (rand() % len);
            vector<int> &w = mp[v[i]];
            int li = -1;
            int ri = -1;
            int wl = w.size();
            for (int inc = 1<<17; inc >= 1; inc /= 2) {
                if (li + inc < wl && w[li + inc] < l) li += inc;
                if (ri + inc < wl && w[ri + inc] <= r) ri += inc;
            }
            if (2 * (ri - li) > len) {
                cout<<v[i]<<endl;
                goto end;
            }
        }
        cout<<-1<<endl;
        end:;
    }
}

Test 1

Group: 1, 2, 3, 4

Verdict: ACCEPTED

Test 2

Group: 1, 2, 3, 4

Verdict: ACCEPTED

Test 3

Group: 1, 3, 4

Verdict: ACCEPTED

Test 4

Group: 2, 3, 4

Verdict: ACCEPTED

Test 5

Group: 2, 3, 4

Verdict: ACCEPTED

Test 6

Group: 2, 3, 4

Verdict: ACCEPTED

Test 7

Group: 3, 4

Verdict: TIME LIMIT EXCEEDED

Test 8

Group: 4

Verdict: ACCEPTED

Test 9

Group: 4

Verdict: ACCEPTED

Test 10

Group: 4

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 3, 4

Verdict: ACCEPTED

Test 12

Group: 4

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3, 4

Verdict: ACCEPTED

Test 14

Group: 4

Verdict: ACCEPTED

Test 15

Group: 4

Verdict: ACCEPTED

Test 16

Group: 4

Verdict: ACCEPTED