59. Spiral Matrix II

Author: Partho Biswas

README.md

@@ -159,7 +159,7 @@ I have solved quite a number of problems from several topics. See the below tabl
 |47| **[48. Rotate Image](https://tinyurl.com/yy3z9hab)** | [Python](https://tinyurl.com/wu6rdaw/48_Rotate_Image.py)| [Must](https://tinyurl.com/tr62top), [Vid  1](https://tinyurl.com/uhnruzt) | Medium | Very important |
 |48| **[362. Design Hit Counter](https://tinyurl.com/sswrcc3)** | [Python](https://tinyurl.com/wu6rdaw/362_Design_Hit_Counter.py), [Swift](https://tinyurl.com/wuja3c4/362_Design_Hit_Counter.swift)| --- | Medium | --- |
 |49| **[289. Game of Life](https://tinyurl.com/y5ujyvu5)** | [Python](https://tinyurl.com/wu6rdaw/289_Game_of_Life.py), [Swift](https://tinyurl.com/wuja3c4/289_Game_of_Life.swift)| --- | Medium | --- |
-|50| **[54. Spiral Matrix](https://tinyurl.com/yy5rnvce)** | [Python](https://tinyurl.com/wu6rdaw/54_Spiral_Matrix.py), [Swift](https://tinyurl.com/wuja3c4/54_Spiral_Matrix.swift)| [Official](https://tinyurl.com/s6np53k) | Medium | --- |
+|50| **[54. Spiral Matrix](https://tinyurl.com/yy5rnvce)** | [Python](https://tinyurl.com/wu6rdaw/54_Spiral_Matrix.py), [Swift](https://tinyurl.com/wuja3c4/54_Spiral_Matrix.swift)| [Official](https://tinyurl.com/s6np53k), [Algoexpert.io](https://www.algoexpert.io/questions/Spiral%20Traverse) | Medium | --- |
 |51| **[380. Insert Delete GetRandom O(1)](https://tinyurl.com/y3urnkfj)** | [Python](https://tinyurl.com/wu6rdaw/380_Insert_Delete_GetRandom_O(1).py), [Swift](https://tinyurl.com/wuja3c4/380_Insert_Delete_GetRandom_O(1).swift)| [Official](https://tinyurl.com/t4t38od) | Medium | --- |
 |52| **[835. Image Overlap](https://tinyurl.com/r9x9nkm)** | [Python](https://tinyurl.com/wu6rdaw/835_Image_Overlap.py), [Swift](https://tinyurl.com/wuja3c4/835_Image_Overlap.swift)| [Art 1](https://tinyurl.com/tx3gd98), [Art 2](https://tinyurl.com/tnmj6du) | Medium | --- |
 |53| **[1051. Height Checker](https://tinyurl.com/scupmnz)** | [Python](https://tinyurl.com/wu6rdaw/1051_Height_Checker.py), [Swift](https://tinyurl.com/wuja3c4/1051_Height_Checker.swift) | --- | Easy |  |
@@ -170,6 +170,7 @@ I have solved quite a number of problems from several topics. See the below tabl
 |59| **[1089. Duplicate Zeros](https://tinyurl.com/vdlwjwa)** | [Python](https://tinyurl.com/wu6rdaw/1089_Duplicate_Zeros.py), [Swift](https://tinyurl.com/wuja3c4/1089_Duplicate_Zeros.swift) | [Art 1](https://tinyurl.com/y3b2ynd4) | Easy | Not so easy and intuitive. Check again |
 |60| [941. Valid Mountain Array](https://tinyurl.com/tgdqrrk) | [Python](https://tinyurl.com/wu6rdaw/941_Valid_Mountain_Array.py), [Swift](https://tinyurl.com/wuja3c4/941_Valid_Mountain_Array.swift) |  | Easy |  |
 |61| [731. My Calendar II](https://tinyurl.com/sde6smv) | [Python](https://tinyurl.com/wu6rdaw/731_My_Calendar_II.py), [Swift](https://tinyurl.com/wuja3c4/731_My_Calendar_II.swift) |  | Medium | Merge interval |
+|62| [59. Spiral Matrix II](https://tinyurl.com/pqfjvm7) | [Python](https://tinyurl.com/wu6rdaw/59_Spiral_Matrix_II.py), [Swift](https://tinyurl.com/wuja3c4/59_Spiral_Matrix_II.swift) |  | Medium | loved it |
 
 
 </p>
@@ -726,7 +727,7 @@ BFS, DFS, Dijkstra, Floyd–Warshall, Bellman-Ford, Kruskal, Prim's, Minimum Spa
 
 ### 1. Arrays
 
-<details><summary>Problem sstatement from AlgoExpert.io with solutions and tutorials/videos</summary>
+<details><summary>Problem statement from AlgoExpert.io with solutions and tutorials/videos</summary>
 <p>
 
 | #  | Title | Solution | Tutorial | Level | Remarks |
@@ -741,6 +742,7 @@ BFS, DFS, Dijkstra, Floyd–Warshall, Bellman-Ford, Kruskal, Prim's, Minimum Spa
 |08| [Zigzag_Traverse](algoexpert.io/questions/Zigzag_Traverse.md) | [Python](algoexpert.io/python/Zigzag_Traverse.py) |
 |08| [Apartment_Hunting](algoexpert.io/questions/Apartment_Hunting.md) | [Python](algoexpert.io/python/Apartment_Hunting.py) |
 |09| [Calendar_Matching](algoexpert.io/questions/Calendar_Matching.md) | [Python](algoexpert.io/python/Calendar_Matching.py) |
+|10| [Spiral_Traverse](algoexpert.io/questions/Spiral_Traverse.md) | [Python](algoexpert.io/python/Spiral_Traverse.py) |
 
 </p>
 </details>

algoexpert.io/python/Linked_List_Construction.py

@@ -1,257 +1,93 @@
-# https://www.algoexpert.io/questions/Linked%20List%20Construction
-# Write a class for a Doubly Linked List.
-
-
-# Definition for doubly-linked list node.
-# class ListNode(object):
-#     def __init__(self, x):
-#         self.val = x
-#         self.next = None
-#         self.prev = prev
-
-class DoublyLinkedList:
-
-    def __init__(self):
-        self.head = None
-        self.tail = None
-
-    # O(1) time | O(1) space
-    def set_head(self, node):
-        if self.head is None:
-            self.head = node
-            self.tail = node
-            return
-        self.insert_before(self.head, node)
-
-    # O(1) time | O(1) space
-    def set_tail(self, node):
-        if self.tail is None:
-            self.set_head(node)
-            return
-        self.insert_after(self.tail, node)
-
-    # O(1) time | O(1) space
-    def insert_before(self, node, node_to_insert):
-        if node_to_insert == self.head and node_to_insert == self.tail:
-            return
-        self.remove(node_to_insert)
-        node_to_insert.prev = node.prev
-        node_to_insert.next = node
-        if node.prev is None:
-            self.head = node_to_insert
-        else:
-            node.prev.next = node_to_insert
-        node.prev = node_to_insert
-
-    # O(1) time | O(1) space
-    def insert_after(self, node, node_to_insert):
-        if node_to_insert == self.head and node_to_insert == self.tail:
-            return
-        self.remove(node_to_insert)
-        node_to_insert.prev = node
-        node_to_insert.next = node.next
-        if node.next is None:
-            self.tail = node_to_insert
-        else:
-            node.next.prev = node_to_insert
-        node.next = node_to_insert
-
-    # O(p) time | O(1) space
-    def insert_at_position(self, position, node_to_insert):
-        if position == 1:
-            self.set_head(node_to_insert)
-            return
-        node = self.head
-        current_position = 1
-        while node is not None and current_position != position:
-            node = node.next
-            current_position += 1
-        if node is not None:
-            self.insert_before(node, node_to_insert)
-        else:
-            self.set_tail(node)
-
-    # O(n) time | O(1) space
-    def remove_nodes_with_value(self, value):
-        node = self.head
-        while node is not None:
-            node_to_remove = node
-            node = node.next
-            if node_to_remove.value == value:
-                self.remove(node_to_remove)
-
-    # O(1) time | O(1) space
-    def remove(self, node):
-        if node == self.head:
-            self.head = self.head.next
-        if node == self.tail:
-            self.tail = self.tail.prev
-        self.remove_node_bindings(node)
-
-    def contains_node_with_value(self,  value):
-        node = self.head
-        while node is not None and node.value != value:
-            node = node.next
-        return node is not None
-
-    def remove_node_bindings(self, node):
-        if node.prev is not None:
-            node.prev.next = node.next
-        if node.next is not None:
-            node.next.prev = node.prev
-        node.next = None
-        node.prev = None
-
-
-
-# -------------------------------------
-
-
+# This is an input class. Do not edit.
 class Node:
     def __init__(self, value):
         self.value = value
         self.prev = None
         self.next = None
 
 
+# Code is OK but test cases are failing. DOn't know why
 class DoublyLinkedList:
     def __init__(self):
         self.head = None
         self.tail = None
 
-    # O(1) time | O(1) space
     def setHead(self, node):
         if self.head is None:
             self.head = node
             self.tail = node
             return
         self.insertBefore(self.head, node)
 
-    # O(1) time | O(1) space
     def setTail(self, node):
         if self.tail is None:
             self.setHead(node)
             return
         self.insertAfter(self.tail, node)
 
-    # O(1) time | O(1) space
     def insertBefore(self, node, nodeToInsert):
         if nodeToInsert == self.head and nodeToInsert == self.tail:
             return
         self.remove(nodeToInsert)
         nodeToInsert.prev = node.prev
         nodeToInsert.next = node
-        if node.prev is None:
+        if not node.prev:
             self.head = nodeToInsert
         else:
             node.prev.next = nodeToInsert
         node.prev = nodeToInsert
 
-    # O(1) time | O(1) space
     def insertAfter(self, node, nodeToInsert):
         if nodeToInsert == self.head and nodeToInsert == self.tail:
             return
         self.remove(nodeToInsert)
         nodeToInsert.prev = node
         nodeToInsert.next = node.next
-        if node.next is None:
+        if not node.next:
             self.tail = nodeToInsert
         else:
             node.next.prev = nodeToInsert
         node.next = nodeToInsert
 
-    # O(p) time | O(1) space
     def insertAtPosition(self, position, nodeToInsert):
         if position == 1:
             self.setHead(nodeToInsert)
             return
         node = self.head
-        currentPosition = 1
-        while node is not None and currentPosition != position:
+        currPos = 1
+        while node and currPos != position:
             node = node.next
-            currentPosition += 1
-        if node is not None:
-            self.insertBefore(node, nodeToInsert)
+            currPos += 1
+        if node:
+            self.insertBefore(nodeToInsert)
         else:
             self.setTail(nodeToInsert)
 
-        # O(n) time | O(1) space
-
     def removeNodesWithValue(self, value):
         node = self.head
-        while node is not None:
+        while node:
             nodeToRemove = node
             node = node.next
             if nodeToRemove.value == value:
                 self.remove(nodeToRemove)
 
-    # O(1) time | O(1) space
     def remove(self, node):
         if node == self.head:
             self.head = self.head.next
         if node == self.tail:
             self.tail = self.tail.prev
         self.removeNodeBindings(node)
 
-    # O(n) time | O(1) space
     def containsNodeWithValue(self, value):
         node = self.head
-        while node is not None and node.value != value:
+        while node and node.value != value:
             node = node.next
         return node is not None
 
     def removeNodeBindings(self, node):
-        if node.prev is not None:
+        if node.prev:
             node.prev.next = node.next
-        if node.next is not None:
+        if node.next:
             node.next.prev = node.prev
         node.prev = None
         node.next = None
-
-
-# ------------------
-# This is an input class. Do not edit.
-class Node:
-    def __init__(self, value):
-        self.value = value
-        self.prev = None
-        self.next = None
-
-
-# Feel free to add new properties and methods to the class.
-class DoublyLinkedList:
-    def __init__(self):
-        self.head = None
-        self.tail = None
-
-    def setHead(self, node):
-        # Write your code here.
-        pass
-
-    def setTail(self, node):
-        # Write your code here.
-        pass
-
-    def insertBefore(self, node, nodeToInsert):
-        # Write your code here.
-        pass
-
-    def insertAfter(self, node, nodeToInsert):
-        # Write your code here.
-        pass
-
-    def insertAtPosition(self, position, nodeToInsert):
-        # Write your code here.
-        pass
-
-    def removeNodesWithValue(self, value):
-        # Write your code here.
-        pass
-
-    def remove(self, node):
-        # Write your code here.
-        pass
-
-    def containsNodeWithValue(self, value):
-        # Write your code here.
-        pass

algoexpert.io/python/Spiral_Traverse.py

@@ -0,0 +1,26 @@
+def spiralTraverse(matrix):
+    result = []
+    sR, eR, sC, eC = 0, len(matrix) - 1, 0, len(matrix[0]) - 1
+    while sR <= eR and sC <= eC:
+        for i in range(sC, eC + 1):
+            result.append(matrix[sR][i])
+
+        for i in range(sR + 1, eR + 1):
+            result.append(matrix[i][eC])
+
+        for i in range(eC - 1, sC - 1, -1):
+            if sR == eR:
+                break
+            result.append(matrix[eR][i])
+
+        for i in range(eR - 1, sR, -1):
+            if sC == eC:
+                break
+            result.append(matrix[i][sC])
+
+        sR += 1
+        eR -= 1
+        sC += 1
+        eC -= 1
+
+    return result

leetcode.com/python/59_Spiral_Matrix_II.py

@@ -0,0 +1,34 @@
+class Solution(object):
+    def generateMatrix(self, n):
+        values = [i for i in range(1, n * n + 1)]
+        matrix = [[0 for _ in range(n)] for _ in range(n)]
+        sR, eR, sC, eC = 0, n - 1, 0, n - 1
+
+        valueIdx = 0
+        while sR <= eR and sC <= eC:
+            for i in range(sC, eC + 1):
+                matrix[sR][i] = values[valueIdx]
+                valueIdx += 1
+
+            for i in range(sR + 1, eR + 1):
+                matrix[i][eC] = values[valueIdx]
+                valueIdx += 1
+
+            for i in range(eC - 1, sC - 1, -1):
+                if sR == eR:
+                    break
+                matrix[eR][i] = values[valueIdx]
+                valueIdx += 1
+
+            for i in range(eR - 1, sR, -1):
+                if sC == eC:
+                    break
+                matrix[i][sC] = values[valueIdx]
+                valueIdx += 1
+
+            sR += 1
+            eR -= 1
+            sC += 1
+            eC -= 1
+
+        return matrix