Time: 2368 ms (5.05%) | Memory: 39.4 MB (5.74%) - LeetSync

Co-authored-by: Joshua Dierickse <joshua.dierickse@gmail.com>

Author: 2 people

84-largest-rectangle-in-histogram/largest-rectangle-in-histogram.py

@@ -0,0 +1,80 @@
+import heapq
+
+class Node:
+    def __init__(self, left, right, height, width):
+        self.left = left
+        self.right = right
+        self.height = height
+        self.width = width
+        self.deleted = False
+
+    def __eq__(self, other):
+        return self.height == other.height
+
+    def __lt__(self, other):
+        return self.height * -1 < other.height * -1
+
+def del_right_node(node):
+    node.width += node.right.width
+    node.height = node.right.height
+    node.right.deleted = True
+    node.right = node.right.right
+    if node.right:
+        node.right.left = node
+
+def del_left_node(node):
+    node.width += node.left.width
+    node.height = node.left.height
+    node.left.deleted = True
+    node.left = node.left.left
+    if node.left:
+        node.left.right = node
+
+def print_ll(node):
+    while node.left:
+        node = node.left
+
+    print("---")
+
+    while node:
+        print("height: ", node.height, ", width", node.width)
+        node = node.right
+
+class Solution:
+    def largestRectangleArea(self, heights: List[int]) -> int:
+        ll = None
+        heap = []
+
+        m = 0
+
+        for height in heights:
+            m = max(m, height)
+            prev = ll
+            ll = Node(ll, None, height, 1)
+            if prev:
+                prev.right = ll
+            heapq.heappush(heap, ll)
+
+        while heap:
+            node = heapq.heappop(heap)
+            if node.deleted:
+                continue
+
+            if node.left and node.right:
+                if node.left.height < node.right.height:
+                    del_right_node(node)
+                else:
+                    del_left_node(node)
+            elif node.left:
+                del_left_node(node)
+            elif node.right:
+                del_right_node(node)
+            else:
+                continue
+
+            heapq.heappush(heap, node)
+
+            m = max(m, node.height * node.width)
+
+        return m
+