Recovery (2010)

1 files changed, 15 insertions, 0 deletions

diff --git a/codechef/chefinsq.py b/codechef/chefinsq.py
new file mode 100755
index 0000000..04fd5ef
--- /dev/null
+++ b/codechef/chefinsq.py
@@ -0,0 +1,15 @@
+#!/usr/bin/env python3
+from bisect import bisect_left, bisect_right
+from functools import reduce
+from math import factorial
+
+
+def c(n, r):
+    return reduce(int.__mul__, range(n, n - r, -1), 1) // factorial(r)
+
+
+for t in range(int(input())):
+    n, k = map(int, input().split())
+    a = sorted(map(int, input().split()))
+    l, r = bisect_left(a, a[k - 1]), bisect_right(a, a[k - 1])
+    print(c(r - l, min(k - l, r - k)))