From f3fc46c2b263e2ca925607cb731375d5b8e87572 Mon Sep 17 00:00:00 2001
From: Xinshuang Jin <jinxinshuang@gmail.com>
Date: Mon, 14 Apr 2025 18:23:35 -0400
Subject: [PATCH] modify rotate_list and skyline

---
 rotate_list.py | 62 +++++++++++++++++++++++++++++++++++++++++++++++++-
 skyline.py     | 38 ++++++++++++++++++++++++++++++-
 2 files changed, 98 insertions(+), 2 deletions(-)

diff --git a/rotate_list.py b/rotate_list.py
index 383245a..c56f8e2 100644
--- a/rotate_list.py
+++ b/rotate_list.py
@@ -1,4 +1,64 @@
 # Add your clarifying questions here
+# Will the value of shift_by always be positive? 
+    # Yes, always a positive shift by 
+# Is the list always non-empty? 
+    # An empty list will just return an empty
+# Will the shift alway be to the right?
+    # Yes, we wil never shift to the left
+# What if the shift_by is larger than our length?
+    # Shift by will be alwasy be less than the length
+    # let group decide
+# Are we allowed to use built ins(pop, insert)?
 
+# if there is only one element in the list, return the list?
+# return None, shift out of bounds
+
+# input : [1, 2, 3] , 2
+# output: [2, 3, 1]\
+#asssert rotate_list([1, 2, 3], 2) = [2, 3, 1]
+
+# input: ['a', 'b', 'c', 'd'] , 1
+# output": ['d','a','b', 'c']
+
+
+# input = [9], 5233
+# output: None, or shift out of bounds  
+
+# Method 1
 def rotate_list(list, shift_by):
-    pass
\ No newline at end of file
+    if not list:
+        return []
+    if len(list) < shift_by:
+        return f"shift_by {shift_by} is out of bounds"
+    if len(list) == 1:
+        return list
+    
+    updated_list = [None] * len(list) # update_list = [None, None, None]
+
+    for i in range(len(list)):
+        if i + shift_by > len(list) - 1:
+            updated_list[i+shift_by-len(list)] = list[i]
+            continue
+        updated_list[i+shift_by] = list[i]
+
+    return updated_list
+
+result = rotate_list(['a', 'b', 'c', 'd'] , 1)
+print(result)
+
+# Method 2 hard code, not add a new list!
+def rotate_list(list, shift_by):
+    if not list:
+        return []
+    if len(list) < shift_by:
+        return f"shift_by {shift_by} is out of bounds"
+    if len(list) == 1:
+        return list
+
+    return list[(len(list) - shift_by): len(list)] + list[0: (len(list) - shift_by)]
+
+
+    # This also works
+    # return list[(len(list) - shift_by): ] + list[: (len(list) - shift_by)]
+result = rotate_list([1, 2, 3] , 2)
+print(result)
diff --git a/skyline.py b/skyline.py
index 20857c3..ceb2c04 100644
--- a/skyline.py
+++ b/skyline.py
@@ -1,4 +1,40 @@
 # Add your clarifying questions here
+# Find smallest in the list, anythin above that is you could seens, order there is ascending order with no repeats
+
+# Only one elemetn in the list? return None
+# if the list if empty? return None
+# if the elemenets are all the same? return None
+# if the elements are not numbers? assume they are all numbers
+
+
+# Given a list [-1, 1, 3, 7, 7, 3] determine which values could be "seen."
+# The output should be: [1,3,7]
+
 
 def skyline(building_list):
-    pass
\ No newline at end of file
+    if not building_list:
+        return None
+    if len(building_list) == 1:
+        return None
+    
+    # bottom_floor = min(building_list, key=lambda element: element)
+    bottom_floor = min(building_list)
+    top_floor = max(building_list)
+
+    seen_list = []
+    previous_floor = float('-inf')
+
+    for floor in building_list:
+        # If it reaches the top floor, nothing else could be seen, exit the loop
+        if floor == top_floor:
+            seen_list.append(floor)
+            break
+        if (floor > bottom_floor) and (floor > previous_floor):
+            seen_list.append(floor)
+            previous_floor = floor
+    
+    return seen_list
+
+
+result = skyline([-1, 1, 3, 7, 7, 3])
+print(result)
\ No newline at end of file