diff --git a/topics/dp/topic.iml b/topics/dp/topic.iml
deleted file mode 100644
index b107a2d..0000000
--- a/topics/dp/topic.iml
+++ /dev/null
@@ -1,11 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<module type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
-    <exclude-output />
-    <content url="file://$MODULE_DIR$">
-      <sourceFolder url="file://$MODULE_DIR$" isTestSource="false" />
-    </content>
-    <orderEntry type="inheritedJdk" />
-    <orderEntry type="sourceFolder" forTests="false" />
-  </component>
-</module>
\ No newline at end of file
diff --git a/topics/dp/dp/knapsack/Knapsack.java b/topics/topics/dp/knapsack/Knapsack.java
similarity index 100%
rename from topics/dp/dp/knapsack/Knapsack.java
rename to topics/topics/dp/knapsack/Knapsack.java
diff --git a/topics/dp/dp/knapsack/SubsetPartition.java b/topics/topics/dp/knapsack/SubsetPartition.java
similarity index 100%
rename from topics/dp/dp/knapsack/SubsetPartition.java
rename to topics/topics/dp/knapsack/SubsetPartition.java
diff --git a/topics/dp/dp/knapsack/SubsetSum.java b/topics/topics/dp/knapsack/SubsetSum.java
similarity index 100%
rename from topics/dp/dp/knapsack/SubsetSum.java
rename to topics/topics/dp/knapsack/SubsetSum.java
diff --git a/topics/dp/dp/knapsack/idea.png b/topics/topics/dp/knapsack/idea.png
similarity index 100%
rename from topics/dp/dp/knapsack/idea.png
rename to topics/topics/dp/knapsack/idea.png
diff --git a/topics/dp/dp/lcs/LongestCommonSubsequence.java b/topics/topics/dp/lcs/LongestCommonSubsequence.java
similarity index 100%
rename from topics/dp/dp/lcs/LongestCommonSubsequence.java
rename to topics/topics/dp/lcs/LongestCommonSubsequence.java
diff --git a/topics/dp/dp/lcs/LongestCommonSubstring.java b/topics/topics/dp/lcs/LongestCommonSubstring.java
similarity index 100%
rename from topics/dp/dp/lcs/LongestCommonSubstring.java
rename to topics/topics/dp/lcs/LongestCommonSubstring.java
diff --git a/topics/dp/dp/lcs/PrintLCS.java b/topics/topics/dp/lcs/PrintLCS.java
similarity index 100%
rename from topics/dp/dp/lcs/PrintLCS.java
rename to topics/topics/dp/lcs/PrintLCS.java
diff --git a/topics/dp/dp/lcs/ShortestCommonSuperSequence.java b/topics/topics/dp/lcs/ShortestCommonSuperSequence.java
similarity index 100%
rename from topics/dp/dp/lcs/ShortestCommonSuperSequence.java
rename to topics/topics/dp/lcs/ShortestCommonSuperSequence.java
diff --git a/topics/dp/dp/problems/LongestPallindromicSubsequence.java b/topics/topics/dp/problems/LongestPallindromicSubsequence.java
similarity index 100%
rename from topics/dp/dp/problems/LongestPallindromicSubsequence.java
rename to topics/topics/dp/problems/LongestPallindromicSubsequence.java
diff --git a/topics/dp/dp/problems/LongestRepeatedSequence.java b/topics/topics/dp/problems/LongestRepeatedSequence.java
similarity index 100%
rename from topics/dp/dp/problems/LongestRepeatedSequence.java
rename to topics/topics/dp/problems/LongestRepeatedSequence.java
diff --git a/topics/dp/dp/problems/MCMMemo.java b/topics/topics/dp/problems/MCMMemo.java
similarity index 100%
rename from topics/dp/dp/problems/MCMMemo.java
rename to topics/topics/dp/problems/MCMMemo.java
diff --git a/topics/dp/dp/problems/MCMRecursive.java b/topics/topics/dp/problems/MCMRecursive.java
similarity index 100%
rename from topics/dp/dp/problems/MCMRecursive.java
rename to topics/topics/dp/problems/MCMRecursive.java
diff --git a/topics/dp/dp/problems/MinOperationsAddAndDelete.java b/topics/topics/dp/problems/MinOperationsAddAndDelete.java
similarity index 100%
rename from topics/dp/dp/problems/MinOperationsAddAndDelete.java
rename to topics/topics/dp/problems/MinOperationsAddAndDelete.java
diff --git a/topics/dp/dp/problems/NumberOfDeletionsToMakeItPallindrome.java b/topics/topics/dp/problems/NumberOfDeletionsToMakeItPallindrome.java
similarity index 100%
rename from topics/dp/dp/problems/NumberOfDeletionsToMakeItPallindrome.java
rename to topics/topics/dp/problems/NumberOfDeletionsToMakeItPallindrome.java
diff --git a/topics/dp/dp/problems/PallindromePartitioning.java b/topics/topics/dp/problems/PallindromePartitioning.java
similarity index 100%
rename from topics/dp/dp/problems/PallindromePartitioning.java
rename to topics/topics/dp/problems/PallindromePartitioning.java
diff --git a/topics/dp/dp/problems/PartitionSumEqualSubsetBottomUp.java b/topics/topics/dp/problems/PartitionSumEqualSubsetBottomUp.java
similarity index 100%
rename from topics/dp/dp/problems/PartitionSumEqualSubsetBottomUp.java
rename to topics/topics/dp/problems/PartitionSumEqualSubsetBottomUp.java
diff --git a/topics/dp/dp/problems/PartitionSumEqualSubsetRecursion.java b/topics/topics/dp/problems/PartitionSumEqualSubsetRecursion.java
similarity index 100%
rename from topics/dp/dp/problems/PartitionSumEqualSubsetRecursion.java
rename to topics/topics/dp/problems/PartitionSumEqualSubsetRecursion.java
diff --git a/topics/dp/dp/problems/ShortestCommonSSPrinted.java b/topics/topics/dp/problems/ShortestCommonSSPrinted.java
similarity index 100%
rename from topics/dp/dp/problems/ShortestCommonSSPrinted.java
rename to topics/topics/dp/problems/ShortestCommonSSPrinted.java
diff --git a/topics/dp/dp/unboundedknapsack/CoinChange.java b/topics/topics/dp/unboundedknapsack/CoinChange.java
similarity index 100%
rename from topics/dp/dp/unboundedknapsack/CoinChange.java
rename to topics/topics/dp/unboundedknapsack/CoinChange.java
diff --git a/topics/dp/dp/unboundedknapsack/MinNumberOfCoins.java b/topics/topics/dp/unboundedknapsack/MinNumberOfCoins.java
similarity index 100%
rename from topics/dp/dp/unboundedknapsack/MinNumberOfCoins.java
rename to topics/topics/dp/unboundedknapsack/MinNumberOfCoins.java
diff --git a/topics/dp/dp/unboundedknapsack/RodCutting.java b/topics/topics/dp/unboundedknapsack/RodCutting.java
similarity index 100%
rename from topics/dp/dp/unboundedknapsack/RodCutting.java
rename to topics/topics/dp/unboundedknapsack/RodCutting.java
diff --git a/topics/dp/dp/unboundedknapsack/readme.md b/topics/topics/dp/unboundedknapsack/readme.md
similarity index 100%
rename from topics/dp/dp/unboundedknapsack/readme.md
rename to topics/topics/dp/unboundedknapsack/readme.md
diff --git a/topics/topics/graph/Cycle.java b/topics/topics/graph/Cycle.java
new file mode 100644
index 0000000..e927539
--- /dev/null
+++ b/topics/topics/graph/Cycle.java
@@ -0,0 +1,46 @@
+package graph;
+
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+
+public class Cycle {
+
+    public void traverseBfs(ArrayList<ArrayList<Integer>> list, int nodes){
+        boolean[] visited = new boolean[nodes];
+        for(int i=0;i<nodes;i++){
+            if(!visited[i]){
+                traverseBfs(list, i, visited);
+            }
+        }
+    }
+
+    private void traverseBfs(ArrayList<ArrayList<Integer>> list, int curr, boolean[] visited) {
+
+        ArrayDeque<Integer> queue = new ArrayDeque<>();
+        queue.add(curr);
+        visited[curr] = true;
+
+        while(!queue.isEmpty())
+        {
+            curr = queue.remove();
+            System.out.println(curr);
+            for(int neigh: list.get(curr))
+            {
+                if(!visited[neigh]){
+                    visited[neigh] = true;
+                    queue.add(neigh);
+                }
+                else{
+                    System.out.println("cycle.");
+                }
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+
+        Graph g = new Graph();
+        ArrayList<ArrayList<Integer>> graph = g.sampleGraph();
+
+    }
+}
diff --git a/topics/topics/graph/Graph.java b/topics/topics/graph/Graph.java
new file mode 100644
index 0000000..783dbbf
--- /dev/null
+++ b/topics/topics/graph/Graph.java
@@ -0,0 +1,27 @@
+package graph;
+
+import java.util.ArrayList;
+
+public class Graph {
+
+    public ArrayList<ArrayList<Integer>> sampleGraph() {
+
+        int[][] graph = new int[][]{{0, 1}, {0, 2}, {1, 2}, {1, 3}, {3, 4}, {2, 4}};
+        return createGraph(graph, 5, true);
+    }
+
+    private ArrayList<ArrayList<Integer>> createGraph(int[][] graph, int nodes, boolean bidirectional) {
+        ArrayList<ArrayList<Integer>> list = new ArrayList<>();
+        for (int i = 0; i < nodes; i++) {
+            list.add(new ArrayList<>());
+        }
+        for(int[] vertex: graph){
+            list.get(vertex[0]).add(vertex[1]);
+            if(bidirectional) {
+                list.get(vertex[1]).add(vertex[0]);
+            }
+        }
+        return list;
+    }
+
+}
diff --git a/topics/topics/graph/Traversal.java b/topics/topics/graph/Traversal.java
new file mode 100644
index 0000000..efcdc0a
--- /dev/null
+++ b/topics/topics/graph/Traversal.java
@@ -0,0 +1,76 @@
+package graph;
+
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Stack;
+
+public class Traversal {
+
+    public void traverseBfs(ArrayList<ArrayList<Integer>> list, int nodes){
+        boolean[] visited = new boolean[nodes];
+        for(int i=0;i<nodes;i++){
+            if(!visited[i]){
+                traverseBfs(list, i, visited);
+            }
+        }
+    }
+
+    private void traverseBfs(ArrayList<ArrayList<Integer>> list, int curr, boolean[] visited) {
+
+        ArrayDeque<Integer> queue = new ArrayDeque<>();
+        queue.add(curr);
+        visited[curr] = true;
+
+        while(!queue.isEmpty())
+        {
+            curr = queue.remove();
+            System.out.println(curr);
+            for(int neigh: list.get(curr))
+            {
+                if(!visited[neigh]){
+                    visited[neigh] = true;
+                    queue.add(neigh);
+                }
+            }
+        }
+    }
+
+    private void traverseDfs(ArrayList<ArrayList<Integer>> list, int nodes){
+        boolean[] visited = new boolean[nodes];
+        for(int i=0;i<nodes;i++){
+            if(!visited[i]){
+                traverseDfs(list, i, visited);
+            }
+        }
+    }
+
+    private void traverseDfs(ArrayList<ArrayList<Integer>> list, int curr, boolean[] visited) {
+        Stack<Integer> stack = new Stack<>();
+        stack.add(curr);
+        visited[curr] = true;
+
+        while(!stack.isEmpty()){
+            curr = stack.pop();
+            System.out.println(curr);
+            for(int neigh: list.get(curr)){
+                if(!visited[neigh]){
+                    visited[neigh] = true;
+                    stack.add(neigh);
+                }
+            }
+        }
+    }
+
+
+    public static void main(String[] args) {
+
+        Graph g = new Graph();
+        ArrayList<ArrayList<Integer>> graph = g.sampleGraph();
+        Traversal traversal = new Traversal();
+        System.out.println("BFS");
+        traversal.traverseBfs(graph, 5);
+        System.out.println("\nDFS");
+        traversal.traverseDfs(graph, 5);
+    }
+
+}
diff --git a/topics/topics/graph/problems/PathWithMaxProbability.java b/topics/topics/graph/problems/PathWithMaxProbability.java
new file mode 100644
index 0000000..80adf0e
--- /dev/null
+++ b/topics/topics/graph/problems/PathWithMaxProbability.java
@@ -0,0 +1,46 @@
+package graph.problems;
+
+import java.util.ArrayDeque;
+
+public class PathWithMaxProbability {
+
+    public static void main(String[] args) {
+
+        int[][] graph = {{0, 1}, {1, 2}, {0, 2}};
+        int n = 3;
+        double[] succProb = new double[]{0.5, 0.5, 0.2};
+        int startNode = 0;
+        int endNode = 3;
+
+        traversal(graph, n, succProb, startNode, endNode);
+
+    }
+
+    private static void traversal(int[][] graph, int n, double[] succProb, int startNode, int endNode) {
+
+        boolean[] visited = new boolean[n];
+        traversal(graph, startNode, endNode, visited);
+
+    }
+
+    //written a plain dfs.. to compute
+    private static void traversal(int[][] graph, int startNode, int endNode, boolean[] visited) {
+
+        ArrayDeque<Integer> queue = new ArrayDeque<>();
+        queue.add(startNode);
+        visited[startNode] = true;
+
+        while(!queue.isEmpty()){
+            Integer top = queue.remove();
+            System.out.println(top+" ");
+            for(int neigh: graph[top]){
+                if(!visited[neigh]){
+                    visited[neigh] = true;
+                    queue.add(neigh);
+                }
+            }
+        }
+
+    }
+
+}
diff --git a/topics/dp/trees/Traversal.java b/topics/topics/trees/Traversal.java
similarity index 100%
rename from topics/dp/trees/Traversal.java
rename to topics/topics/trees/Traversal.java
diff --git a/topics/dp/trees/TreeNode.java b/topics/topics/trees/TreeNode.java
similarity index 100%
rename from topics/dp/trees/TreeNode.java
rename to topics/topics/trees/TreeNode.java
diff --git a/topics/dp/trees/bst/BinarySearchTree.java b/topics/topics/trees/bst/BinarySearchTree.java
similarity index 100%
rename from topics/dp/trees/bst/BinarySearchTree.java
rename to topics/topics/trees/bst/BinarySearchTree.java
diff --git a/topics/dp/trees/tree/CreateTree.java b/topics/topics/trees/tree/CreateTree.java
similarity index 100%
rename from topics/dp/trees/tree/CreateTree.java
rename to topics/topics/trees/tree/CreateTree.java
diff --git a/topics/dp/trees/tree/PathSum.java b/topics/topics/trees/tree/PathSum.java
similarity index 100%
rename from topics/dp/trees/tree/PathSum.java
rename to topics/topics/trees/tree/PathSum.java
diff --git a/topics/dp/trees/tree/Tree.java b/topics/topics/trees/tree/Tree.java
similarity index 100%
rename from topics/dp/trees/tree/Tree.java
rename to topics/topics/trees/tree/Tree.java