1462A - Favorite Sequence
15 Dec 2020 — Tags: easy,implementation — URLReverse the operation.
Time complexity: $O(n)$
Memory complexity: $O(n)$
Click to show code.
using namespace std;
using ll = long long;
using ii = pair<int, int>;
using vi = vector<int>;
template <typename InputIterator,
typename T = typename iterator_traits<InputIterator>::value_type>
void read_n(InputIterator it, int n)
{
copy_n(istream_iterator<T>(cin), n, it);
}
template <typename InputIterator,
typename T = typename iterator_traits<InputIterator>::value_type>
void write(InputIterator first, InputIterator last, const char *delim = "\n")
{
copy(first, last, ostream_iterator<T>(cout, delim));
}
int main(void)
{
ios::sync_with_stdio(false), cin.tie(NULL);
int t;
cin >> t;
while (t--)
{
int n;
cin >> n;
vi a(n), ans(n);
read_n(begin(a), n);
int i = 0, l = 0, r = n - 1;
while (l < r)
{
ans[i++] = a[l++];
ans[i++] = a[r--];
}
if (l == r)
ans[i] = a[l];
write(begin(ans), end(ans), " "), cout << endl;
}
return 0;
}