Concentric Tubes

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define pb push_back
#define VI vector<int>
#define AR(x) array<int, x>
#define MX vector<VI >
#define all(x) x.begin(), x.end()
#define IOS cin.tie(0)->sync_with_stdio(0)

using namespace std;

int main(){

    int n;
    cin >> n;

    VI r(n), R(n), ord(n);
    for(int &i : r) cin >> i;
    for(int &i : R) cin >> i;

    iota(all(ord), 0);
    sort(all(ord), [&](int l, int b){ return R[l] < R[b]; });

    VI ans(1, ord[0]+1);
    int p = ord[0];
    for(int i : ord){
        if(r[i] >= R[p]){
            ans.pb(i+1);
            p = i;
        }
    }

    cout << ans.size() << '\n';
    for(int i : ans) cout << i << ' ';
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED