dailyprogrammer 390

python/dailyprogrammer/#390 - Number of 1s.py

@@ -0,0 +1,16 @@
+def count1(n):
+	x = str(n)
+	count = 0
+	for index, digit in enumerate(x[::-1]):
+		digit = int(digit)
+		if digit != 0:
+			if digit == 1:
+				numberAfter = x[len(x) - index:] or '0'
+				count += int(numberAfter) + 1
+			else:
+				count += 10 ** index
+		count += int(10 ** (index - 1) * index * digit)
+	return count
+
+
+print(count1(3**35))

python/dailyprogrammer/readme.md

@@ -5,6 +5,9 @@
 
 [The Subreddit](https://reddit.com/r/dailyprogrammer)
 
+- #390 - Number of 1s
+    - [Solution](%23390%20-%20Number%20of%201s.py)
+    - [Reddit Post](https://www.reddit.com/r/dailyprogrammer/comments/neg49j/20210517_challenge_390_difficult_number_of_1s/)
 - #391 - ABACABA
     - [Solution](%23391%20-%20ABACABA.py)
     - [Reddit Post](https://www.reddit.com/r/dailyprogrammer/comments/njxq95/20210524_challenge_391_easy_the_abacaba_sequence/)