add

Author: maityamit

013 - Tries and Huffman Coding/Trie.h

@@ -0,0 +1,30 @@
+class Trie{
+	TrieNode *root;
+	public:
+		Trie(){
+			root = new TrieNode('\0');
+		}
+		void insertWord(string word){
+			insertWordHelper(root,word);
+		}
+		void insertWordHelper(TrieNode* root,string word){
+			//Base Case
+			if(word.size()==0){
+				root->isTerminal=true;
+				return;
+			}
+			
+			//small calc
+			int index = word[0]-'a';
+			TrieNode *child;
+			if(root->children[index] !=NULL){
+				child = root->children(index);
+			}else{
+				child = new TrieNode(word[0]);
+				root->children[index] = child;
+			}
+			
+			//Recusrsive call
+			insertWord(child,word.substr(1));
+		}
+};

013 - Tries and Huffman Coding/TrieNode.h

@@ -6,6 +6,7 @@ class TrieNode{
 		TrieNode(char data){
 			thos->data = data;
 			children = new TrieNode*[26];
+			for(int i=0;i<26;i++) children[i]=NULL;
 			isTerminal = false;
 		}
 };

013 - Tries and Huffman Coding/trie_practice.cpp

@@ -0,0 +1,6 @@
+#include<iostream>
+#include"TrieNode.h"
+using namespace std;
+int main(){
+	return 0;
+}

016 - Graphs/001 DFS traversal.cpp

@@ -0,0 +1,41 @@
+#include<iostream>
+using namespace std;
+
+void print(int **edges,int n,int sv,bool *visited){
+	cout<<sv<<" ";
+	visited[sv]=true;
+	for(int i=0;i<n;i++){
+		if(i==sv) continue;
+		if(edges[sv][i]==1){
+			if(visited[i]) continue;
+			print(edges,n,i,visited);
+		}
+	}
+}
+
+int main(){
+	int n,e;
+	cin>>n>>e;
+	int **edges = new int*[n];
+	for(int i=0;i<n;i++){
+		edges[i]=new int[n];
+		for(int j=0;j<n;j++){
+			edges[i][j]=0;
+		}
+	}
+	
+	for(int i=0;i<e;i++){
+		int fi,si;
+		cin>>fi>>si;
+		edges[fi][si]=1;
+		edges[si][fi]=1;
+	}
+	
+	bool *visited = new bool[n];
+	for(int i=0;i<n;i++){
+		visited[i]=false;
+	}
+	
+	print(edges,n,0,visited);
+	return 0;
+}

016 - Graphs/002 BFS traversal.cpp

@@ -0,0 +1,48 @@
+#include<iostream>
+#include<queue>
+using namespace std;
+
+void printBFS(int **edges,int n,int sv,bool *visited){
+	queue<int> pendingVertices;
+	pendingVertices.push(sv);
+	visited[sv]=true;
+	while(pendingVertices.size()!=0){
+		int temp = pendingVertices.front();
+		pendingVertices.pop();
+		cout<<temp<<" ";
+		for(int i=0;i<n;i++){
+			if(i==temp) continue;
+			if(edges[temp][i]==1 && !visited[i]){
+				pendingVertices.push(i);
+				visited[i]=true;
+			}
+		}
+	}
+}
+
+int main(){
+	int n,e;
+	cin>>n>>e;
+	int **edges = new int*[n];
+	for(int i=0;i<n;i++){
+		edges[i]=new int[n];
+		for(int j=0;j<n;j++){
+			edges[i][j]=0;
+		}
+	}
+	
+	for(int i=0;i<e;i++){
+		int fi,si;
+		cin>>fi>>si;
+		edges[fi][si]=1;
+		edges[si][fi]=1;
+	}
+	
+	bool *visited = new bool[n];
+	for(int i=0;i<n;i++){
+		visited[i]=false;
+	}
+	
+	printBFS(edges,n,0,visited);
+	return 0;
+}

016 - Graphs/003 disconncted_graph_BFS,DFS.cpp

@@ -0,0 +1,79 @@
+#include<iostream>
+#include<queue>
+using namespace std;
+
+void printDFS(int **edges,int n,int sv,bool *visited){
+	cout<<sv<<" ";
+	visited[sv]=true;
+	for(int i=0;i<n;i++){
+		if(i==sv) continue;
+		if(edges[sv][i]==1){
+			if(visited[i]) continue;
+			printDFS(edges,n,i,visited);
+		}
+	}
+}
+
+void printBFS(int **edges,int n,int sv,bool *visited){
+	queue<int> pendingVertices;
+	pendingVertices.push(sv);
+	visited[sv]=true;
+	while(pendingVertices.size()!=0){
+		int temp = pendingVertices.front();
+		pendingVertices.pop();
+		cout<<temp<<" ";
+		for(int i=0;i<n;i++){
+			if(i==temp) continue;
+			if(edges[temp][i]==1 && !visited[i]){
+				pendingVertices.push(i);
+				visited[i]=true;
+			}
+		}
+	}
+}
+
+void BFS(int **edges,int n){
+	bool *visited = new bool(n);
+	for(int i=0;i<n;i++) visited[i]=false;
+	for(int i=0;i<n;i++){
+		if(!visited[i]){
+			printBFS(edges,n,i,visited);
+		}
+	}
+}
+
+void DFS(int **edges,int n){
+	bool *visited = new bool(n);
+	for(int i=0;i<n;i++) visited[i]=false;
+	for(int i=0;i<n;i++){
+		if(!visited[i]){
+			printDFS(edges,n,i,visited);
+		}
+	}
+}
+
+int main(){
+	int n,e;
+	cin>>n>>e;
+	int **edges = new int*[n];
+	for(int i=0;i<n;i++){
+		edges[i]=new int[n];
+		for(int j=0;j<n;j++){
+			edges[i][j]=0;
+		}
+	}
+	
+	for(int i=0;i<e;i++){
+		int fi,si;
+		cin>>fi>>si;
+		edges[fi][si]=1;
+		edges[si][fi]=1;
+	}
+	
+	cout<<"DFS"<<endl;
+	DFS(edges,n);
+	cout<<"\nBFS"<<endl;
+	BFS(edges,n);
+	
+	return 0;
+}

016 - Graphs/004 hasPath.cpp

@@ -0,0 +1,55 @@
+#include<iostream>
+#include<queue>
+using namespace std;
+
+bool hasPath(int **edges,int n,int sv,bool *visited,int ei){
+	queue<int> pendingVertices;
+	pendingVertices.push(sv);
+	visited[sv]=true;
+	while(pendingVertices.size()!=0){
+		int temp = pendingVertices.front();
+		pendingVertices.pop();
+		if(temp==ei){
+			return true;
+			break;
+		}
+		for(int i=0;i<n;i++){
+			if(i==temp) continue;
+			if(edges[temp][i]==1 && !visited[i]){
+				pendingVertices.push(i);
+				visited[i]=true;
+			}
+		}
+	}
+	return false;
+}
+
+int main(){
+	int n,e;
+	cin>>n>>e;
+	int **edges = new int*[n];
+	for(int i=0;i<n;i++){
+		edges[i]=new int[n];
+		for(int j=0;j<n;j++){
+			edges[i][j]=0;
+		}
+	}
+	
+	for(int i=0;i<e;i++){
+		int fi,si;
+		cin>>fi>>si;
+		edges[fi][si]=1;
+		edges[si][fi]=1;
+	}
+	
+	int si,ei;
+    cin>>si>>ei;
+	
+	bool *visited = new bool[n];
+	for(int i=0;i<n;i++){
+		visited[i]=false;
+	}
+	
+	cout<<hasPath(edges,n,si,visited,ei);
+	return 0;
+}