332. Reconstruct Itinerary

Author: Partho Biswas

README.md

@@ -425,6 +425,7 @@ BFS, DFS, Dijkstra, Union Find, Kruskal, Prim's, Minimum Spanning Tree, Topologi
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+|19| **[332. Reconstruct Itinerary](https://tinyurl.com/gn2mv3k)** | [Python](https://tinyurl.com/wu6rdaw/332_Reconstruct_Itinerary.py)|  [Vid 1](https://tinyurl.com/w47evd9), [Vid 2](https://tinyurl.com/uvop34p), [Art 1](https://tinyurl.com/tsy24pl), [Art 2](https://tinyurl.com/srazxo3), [Art 3](https://tinyurl.com/wluob5j), **[Art 4](https://tinyurl.com/y4s9crf6)** | Medium | **Important, Learned new things. Directed Graph. Eulerian path and top Sort** |
 
 
 </p>

leetcode.com/python/332_Reconstruct_Itinerary.py

@@ -0,0 +1,22 @@
+# Source: https://tinyurl.com/tsy24pl
+from collections import defaultdict
+class Solution(object):
+    def findItinerary(self, tickets):
+        """
+        :type tickets: List[List[str]]
+        :rtype: List[str]
+        """
+        graph = defaultdict(list)
+        for source, destination in tickets:
+            graph[source].append(destination)
+        for source in graph.keys():
+            graph[source].sort(reverse=True)
+        stack = ["JFK",]
+        result = []
+        while stack:
+            node = stack[-1]
+            if node in graph and len(graph[node]) > 0:
+                stack.append(graph[node].pop())
+            else:
+                result.append(stack.pop())
+        return result[::-1]