Update num_ones.md

Author: ratulb

docs/num_ones.md

@@ -8,6 +8,13 @@ fn count_bits(mut num: Int) -> Int:
 		num = num >> 1
 	return result
 
+fn count_bits2(mut num: Int) -> Int:
+	result = 0
+	while num:
+		result += num & 1
+		num >>= 1
+	return result
+
 from testing import assert_equal
 
 fn main() raises:
@@ -17,6 +24,12 @@ fn main() raises:
 	assert_equal(1, count_bits(num))
 	num = 2147483645
 	assert_equal(30, count_bits(num))
+	num = 11
+	assert_equal(3, count_bits2(num))
+	num = 128
+	assert_equal(1, count_bits2(num))
+	num = 2147483645
+	assert_equal(30, count_bits2(num))
 ```
 
 [Soure](https://github.com/ratulb/mojo_programming/blob/main/codes/num_ones.mojo)