diff --git a/medium/adding_spaces_to_a_string.py b/medium/adding_spaces_to_a_string.py
new file mode 100644
index 0000000..43970d6
--- /dev/null
+++ b/medium/adding_spaces_to_a_string.py
@@ -0,0 +1,14 @@
+# https://leetcode.com/problems/adding-spaces-to-a-string
+from typing import List
+
+class Solution:
+    def addSpaces(self, s: str, spaces: List[int]) -> str:
+        result = []
+        last_index = 0
+        for index in spaces:
+            result.append(s[last_index:index])
+            result.append(" ")
+            last_index = index
+        result.append(s[last_index:len(s)])
+        return "".join(result)
+