多观察数据，发现当子数组中元素个数 >= 5 时一定不满足条件，因此枚举子数组个数为 3， 4 即可
#include #include #include #include #include #include using namespace std; typedef long long ll; const int N = 2e5 + 10; const int INF = 2e9; int n; int a[N]; bool check(int l, int r) { for (int i = l; i <= r; i++) for (int j = i + 1; j <= r; j++) for (int k = j + 1; k <= r; k++) { if (a[i] <= a[j] && a[j] <= a[k]) return false; if (a[i] >= a[j] && a[j] >= a[k]) return false; } return true; } int main() { ios::sync_with_stdio(false), cin.tie(0), cout.tie(0); int T; cin >> T; while(T--) { cin >> n; for (int i = 1; i <= n; i++) cin >> a[i]; int ans = 2 * n - 1; for (int l = 1; l + 2 <= n; l++) if (check(l, l + 2)) ans++; for (int l = 1; l + 3 <= n; l++) if (check(l, l + 3)) ans++; cout << ans << endl; } return 0; }