Added Trie

Data-Structures/LinkedList.cpp

@@ -0,0 +1,95 @@
+/* Linked List
+This is basic data structure which helps you to understand
+the way of writing data structures. It may be basic but presents
+many concepts of dynamic structures
+
+Insert: O(n)
+Find: O(n)
+Delete: O(n)
+Change Element: O(n)
+Print: O(n)
+*/
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+struct LinkedList 
+{
+    int value;
+    LinkedList *next;
+    LinkedList(int val)
+    {
+        this->value=val;
+        this->next=NULL;
+    }
+};
+
+void Insert(LinkedList *&root, int value)
+{
+    if(root==NULL)
+    {
+        root=new LinkedList(value);
+    }
+    else
+    {
+        LinkedList *tmp = root;
+        while(tmp->next!=NULL)
+        {
+            tmp = tmp->next;
+        }
+        tmp->next=new LinkedList(value);
+    }
+}
+LinkedList* Find(LinkedList *root, int value)
+{
+    while(root!=NULL && root->value!=value)
+    {
+        root=root->next;
+    }
+    return root;
+}
+void Delete(LinkedList *&root, int value)
+{
+    if(root==NULL)return;
+    if(root->value==value)
+    {
+        LinkedList *tmp = root;
+        root=root->next;
+        delete tmp;
+    }
+    LinkedList *tmp = root;
+    while(tmp!=NULL && tmp->next!=NULL && tmp->next->value!=value)
+    {
+        tmp=tmp->next;
+    }
+    if(tmp!=NULL)
+    {
+        LinkedList *tmp2 = tmp->next;
+        tmp->next = tmp->next->next;
+        delete tmp2;
+    }
+}
+void Print(LinkedList *root)
+{
+    while(root!=NULL)
+    {
+        cout<<root->value<<" ";
+        root=root->next;
+    }
+    cout<<endl;
+}
+int main()
+{
+    //Driver Code Lets test this
+    LinkedList *root = NULL;
+    Insert(root,5);
+    Insert(root,6);
+    Insert(root,10);
+    Insert(root,9);
+    Print(root);
+    Delete(root,10);
+    Print(root);
+    cout<<Find(root,7)<<endl;
+    cout<<Find(root,5)<<endl;
+}

Data-Structures/Trie.cpp

@@ -0,0 +1,98 @@
+/* Trie or Prefix Tree is a data structure with
+which you can make fast dictionary of words and 
+search which word is in it or isn't 
+Time complexity:
+Insert: O(n)
+Check: O(n)
+Remove: O(n)
+Where n is the length of given string
+*/
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+struct Trie
+{
+    int childrenC;
+    Trie* children[30];
+    bool endOfWord;
+    Trie()
+    {
+        this->childrenC=0;
+        this->endOfWord=false;
+        for(int i=0;i<30;i++)
+        {
+            this->children[i]=NULL;
+        }
+    }
+};
+void Insert(Trie *&root, string word)
+{
+    Trie* tmp = root;
+    for(int i=0;i<word.size();i++)
+    {
+        if(tmp->children[word[i]-'a']==NULL)
+        {
+           tmp->childrenC++;
+           tmp->children[word[i]-'a']=new Trie(); 
+        }
+        tmp=tmp->children[word[i]-'a'];
+        if(i==word.size()-1)
+        {
+             tmp->endOfWord=true;
+        }
+    }
+}
+bool Check(Trie *root, string word)
+{
+    bool result=true;
+    for(int i=0;i<word.size();i++)
+    {
+        if(root->children[word[i]-'a']==NULL)
+        {
+            result=false;
+            break;
+        } 
+        root = root->children[word[i]-'a'];
+        if(i==word.size()-1)
+        {
+            result = root->endOfWord;
+        }
+    }
+    return result;
+}
+bool RemoveAPI(Trie* &cur,string word,int idx)
+{
+    if(cur==NULL)return false;
+    if(idx==word.size())
+    {
+        cur->endOfWord=false;
+    }
+    else
+    {
+        bool result = RemoveAPI(cur->children[word[idx]-'a'],word,idx+1);
+        if(result)
+        {
+            cur->childrenC--;
+            delete cur->children[word[idx]-'a'];
+        }
+    }
+    return cur->childrenC==0;
+}
+void Remove(Trie* &root,string word)
+{
+    RemoveAPI(root,word,0);
+}
+int main()
+{
+    //Driver code.
+    Trie* root = new Trie();
+    Insert(root,"test");
+    Insert(root,"testa");
+    cout<<Check(root,"test")<<endl;
+    cout<<Check(root,"tes")<<endl;
+    Remove(root,"testa");
+    cout<<Check(root,"testa")<<endl;
+    cout<<Check(root,"test")<<endl;
+}