From a625cf7110bea62767733f80189b317a195b4cd0 Mon Sep 17 00:00:00 2001
From: Shrey03 <pshrey619@gmail.com>
Date: Sat, 15 Jan 2022 23:25:52 -0500
Subject: [PATCH] commit 12

---
 Random.py | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Random.py

diff --git a/Random.py b/Random.py
new file mode 100644
index 0000000..166c010
--- /dev/null
+++ b/Random.py
@@ -0,0 +1,49 @@
+# An efficient python3 program
+# to randomly select a number
+# from stream of numbers.
+import random
+
+# A function to randomly select a item
+# from stream[0], stream[1], .. stream[i-1]
+def selectRandom(x):
+	
+	# The resultant random number
+	res = 0;
+	
+	# Count of numbers visited
+	# so far in stream
+	count = 0;
+
+	# increment count of numbers
+	# seen so far
+	count += 1;
+
+	# If this is the first element
+	# from stream, return it
+	if (count == 1):
+		res = x;
+	else:
+		
+		# Generate a random number
+		# from 0 to count - 1
+		i = random.randrange(count);
+
+		# Replace the prev random number
+		# with new number with 1/count
+		# probability
+		if (i == count - 1):
+			res = x;
+	return res;
+
+# Driver Code
+stream = [1, 2, 3, 4];
+n = len(stream);
+
+# Use a different seed value
+# for every run.
+for i in range (n):
+	print("Random number from first",
+		(i + 1), "numbers is",
+		selectRandom(stream[i]));
+
+# This code is contributed by mits