Create Trie.cpp

DSA/DSA-CPP/Trie/Trie.cpp

@@ -0,0 +1,67 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+struct trie{
+	struct trie* child[26];
+	bool is_end;
+	trie(){
+		memset(child,0,sizeof(child));
+		is_end=false;
+	}
+};
+
+struct trie* root;
+//inserts a word to the trie
+void insert(string s){
+	struct trie* temp=root;
+	//traverses over each character
+	//if the character already exists then it simply iterates over
+	//otherwise creates a new node and inserts the character
+	for(char c: s){
+		if(!temp->child[c-'a'])
+			temp->child[c-'a']=new trie;
+		temp=temp->child[c-'a'];
+	}
+	//sets the last letter's boolean value to true
+	temp->is_end=true;
+}
+//returns true if the word exists, false otherwise
+bool check(string s){
+	struct trie* temp=root;
+	//iterates over the character of the word 
+	for(char c: s){
+		//if at any point the char of the word being check is not found it return false
+		if(!temp->child[c-'a'])
+			return false;
+		temp=temp->child[c-'a'];
+	}
+	//returns the last letters boolean value 
+	return temp->is_end;
+}
+
+int main(){
+	ios_base::sync_with_stdio(false);
+	cin.tie(NULL);
+	root=new trie;	
+	int n;
+	cout << "Input the number of words in the List" << endl;
+	cin >> n;
+	string word;
+	cout<<"Enter the words"<<endl;
+	//words that are being inserted to trie.
+	for(int i=0; i<n; i++){
+		cin >> word ;
+		insert(word);
+	}
+	cout << "Enter the number of words you want to check exist in the List" << endl;
+	int m;
+	cin >> m;
+	//the words to be checked
+	for(int i=0; i<m; i++){
+		cin >> word ;
+		if(check(word))
+			cout<< "This word exist in the list" <<endl;
+		else
+			cout<< "This word does not exist in the list"<<endl;
+	}
+}