Merge pull request fnplus#441 from amitrajitbose/trie-python

Add Trie implementation in Python

Author: jenistenxavier

Data Structures/Trie/Trie.py

@@ -0,0 +1,48 @@
+
+class TrieNode(object):
+    def __init__(self):
+        self.children = [] #will be of size = 26
+        self.isLeaf = False
+    
+    def getNode(self):
+        p = TrieNode() #new trie node
+        p.children = []
+        for i in range(26):
+            p.children.append(None)
+        p.isLeaf = False
+        return p
+    
+    def insert(self, root, key):
+        key = str(key)
+        pCrawl = root
+        for i in key:
+            index = ord(i)-97
+            if(pCrawl.children[index] == None):
+                # node has to be initialised
+                pCrawl.children[index] = self.getNode()
+            pCrawl = pCrawl.children[index]
+        pCrawl.isLeaf = True #marking end of word
+    
+    def search(self, root, key):
+        #print("Searching %s" %key) #DEBUG
+        pCrawl = root
+        for i in key:
+            index = ord(i)-97
+            if(pCrawl.children[index] == None):
+                return False
+            pCrawl = pCrawl.children[index]
+        if(pCrawl and pCrawl.isLeaf):
+            return True
+
+def main():
+    root = TrieNode().getNode()
+    root.insert(root, "elephant")
+    root.insert(root, "tiger")
+    root.insert(root, "timothy")
+    search = input("Enter the word to search for: ")
+    if root.search(root, search):
+        print("The word:", search, "exists")
+    else:
+        print("The given word doesnt exist")
+if __name__ == '__main__':
+    main()