#include <bits/stdc++.h>
using i8 = std::int8_t;
using i16 = std::int16_t;
using i32 = std::int32_t;
using i64 = std::int64_t;
using u8 = std::uint8_t;
using u16 = std::uint16_t;
using u32 = std::uint32_t;
using u64 = std::uint64_t;
auto SolveTest() -> void {
  int n;
  std::cin >> n;
  std::vector<int> a(n);
  for (auto &elem : a) {
    std::cin >> elem;
  }
  std::set<int> numbers(std::begin(a), std::end(a));
  for (auto it = std::begin(numbers); std::next(it) != std::end(numbers);
       ++it) {
    if (std::abs(*it - *std::next(it)) > 1) {
      std::cout << "NO\n";
      return;
    }
  }
  std::cout << "YES\n";
}
int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(nullptr);
  std::cout.tie(nullptr);
  i32 test_count;
  std::cin >> test_count;
  for (i32 t = 0; t < test_count; ++t) {
    SolveTest();
  }
}
