记录编号	611456	评测结果	AAAAAAAAAA
题目名称	[THUPC 2025 pre] Harmful Machine Learning	最终得分	100
用户昵称	LikableP	是否通过	通过
代码语言	C++	运行时间	0.734 s
提交时间	2026-01-30 21:06:44	内存使用	1.71 MiB

#include <cstdio>
#include <cctype>

int read() {
  int res = 0, f = 1;
  char ch = getchar();
  for (; !isdigit(ch); ch = getchar()) if (ch == '-') f = -1;
  for (; isdigit(ch); ch = getchar()) res = (res << 3) + (res << 1) + (ch ^ 48);
  return res * f;
}

#include <algorithm>

const int MAXN = 1e5 + 10;

int T;
int n, m;
int a[MAXN], b[MAXN];

bool check(int mid) {
  int sum = 0;
  for (int i = 1; i <= n; ++i) {
    b[i] = a[i] >= mid;
    sum += !b[i];
  }
  return b[m - 1] + b[m] + b[m + 1] >= 2 || sum <= 2;
}

int main() {
  #ifdef LOCAL
    freopen("!input.in", "r", stdin);
    freopen("!output.out", "w", stdout);
  #else
    freopen("thupc_2025_pre_machine.in", "r", stdin);
    freopen("thupc_2025_pre_machine.out", "w", stdout);
  #endif

  T = read();
  while (T--) {
    n = read(), m = read();
    for (int i = 1; i <= n; ++i) a[i] = read();

    if (n <= 3) {
      printf("%d\n", *std::max_element(a + 1, a + n + 1));
      continue;
    }

    b[0] = b[n + 1] = 0;
    int l = 0, r = 1000000000, ans;
    while (l <= r) {
      int mid = l + ((r - l) >> 1);
      if (check(mid)) {
        ans = mid;
        l = mid + 1;
      } else {
        r = mid - 1;
      }
    }

    printf("%d\n", ans);
  }
  return 0;
}