From a57809af9c7611ae119b44b3279fee6f7ce7049c Mon Sep 17 00:00:00 2001
From: prathmesh1199 <51616294+prathmesh1199@users.noreply.github.com>
Date: Sat, 26 Oct 2019 14:48:28 +0530
Subject: [PATCH] Added binomial coefficient (#1467)

* Added binomial coefficient

* Format code with psf/black and add a doctest
---
 maths/binomial_coefficient.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 maths/binomial_coefficient.py

diff --git a/maths/binomial_coefficient.py b/maths/binomial_coefficient.py
new file mode 100644
index 000000000..4def04149
--- /dev/null
+++ b/maths/binomial_coefficient.py
@@ -0,0 +1,20 @@
+def binomial_coefficient(n, r):
+    """
+    Find binomial coefficient using pascals triangle.
+
+    >>> binomial_coefficient(10, 5)
+    252
+    """
+    C = [0 for i in range(r + 1)]
+    # nc0 = 1
+    C[0] = 1
+    for i in range(1, n + 1):
+        # to compute current row from previous row.
+        j = min(i, r)
+        while j > 0:
+            C[j] += C[j - 1]
+            j -= 1
+    return C[r]
+
+
+print(binomial_coefficient(n=10, r=5))