added more problems

AlveeM · AlveeM · commit bc04345cff4e · 2020-12-05T13:50:54.000-05:00
diff --git a/prynatas/0020_merge_intervals.py b/prynatas/0020_merge_intervals.py
@@ -0,0 +1,31 @@
+class Solution:
+    def merge(self, intervals):
+        # check if single interval and return input if true
+        if len(intervals) <= 1: return intervals
+        
+        # sort the intervals based on start time
+        # JavaScript: intervals.sort((a, b) => a[0] - b[0])
+        intervals.sort(key=lambda interval: interval[0])
+        # declare a variable to track new intervals
+        new_intervals = []
+        # declare a variable to store last start time
+        last_start = intervals[0][0]
+        # declare a variable to store last end time
+        last_end = intervals[0][1]
+        
+        # iterate through intervals starting at the 2nd interval
+        for i in range(1, len(intervals)):
+            cur_interval = intervals[i]
+            # if overlapping; cur_interval[0] -> current interval's start time
+            if cur_interval[0] <= last_end:
+                last_end = max(last_end, cur_interval[1])
+            else:
+                new_intervals.append([last_start, last_end])
+                last_start = cur_interval[0]
+                last_end = cur_interval[1]
+        
+        # add the last interval to the new intervals
+        new_intervals.append([last_start, last_end])
+        
+        # return new intervals
+        return new_intervals
diff --git a/prynatas/0021_binary_tree_level_order_traversal.py b/prynatas/0021_binary_tree_level_order_traversal.py
@@ -0,0 +1,44 @@
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, val=0, left=None, right=None):
+#         self.val = val
+#         self.left = left
+#         self.right = right
+
+from collections import deque
+
+class Solution:
+    def levelOrder(self, root):
+        if not root: return None
+        
+        # create a queue
+        queue = deque()
+        # enque the root
+        queue.append(root)
+        # declare a variable to store level arrays (result)
+        result = []
+        
+        # loop while queue is not empty
+        while queue:
+            # declare a variable to store level values (level)
+            level = []
+            # for each node in queue
+            for _ in range(len(queue)):
+                # deque the node
+                node = queue.popleft()
+                # append the node value to level
+                level.append(node.val)
+                # if there's a left node
+                if node.left:
+                    # enqueue the left node
+                    queue.append(node.left)
+                # if there's a right node
+                if node.right:
+                    # enqueue the right node
+                    queue.append(node.right)
+
+            # append level to result
+            result.append(level)
+        
+        # return result
+        return result
