From c583b049847b7bf1fc8411e4a08a5ec592af33c1 Mon Sep 17 00:00:00 2001
From: Evan Ferrao <evanferrao@gmail.com>
Date: Sat, 14 Feb 2026 15:24:35 +0530
Subject: [PATCH] keep code consistent

---
 Graphs/CycleDetectionBFS.java | 75 ++++++++++++++++++-----------------
 Graphs/CycleDetectionDFS.java | 58 +++++++++++++--------------
 2 files changed, 65 insertions(+), 68 deletions(-)

diff --git a/Graphs/CycleDetectionBFS.java b/Graphs/CycleDetectionBFS.java
index 48eb2a8..80f5c50 100644
--- a/Graphs/CycleDetectionBFS.java
+++ b/Graphs/CycleDetectionBFS.java
@@ -1,67 +1,68 @@
 import java.util.*;
+import java.io.*;
 
-public class CycleDetectionBFS {
+class Main {
 
-    static class Pair {
-        int first;
-        int second;
+    // helper structure
+    static class Node{
+        int node;
+        int parent;
 
-        Pair(int first, int second) {
-            this.first = first;
-            this.second = second;
+        Node(int node, int parent){
+            this.node = node;
+            this.parent = parent;
         }
     }
 
-    public static boolean bfs(int src, int V, ArrayList<ArrayList<Integer>> adj,boolean[] vis) {
+    public static boolean bfs(int src, int V,
+                              ArrayList<ArrayList<Integer>> adj,
+                              boolean visited[]){
 
-        vis[src] = true;
-        Queue<Pair> q = new LinkedList<>();
-        q.add(new Pair(src, -1));
+        visited[src] = true;
 
-        while (!q.isEmpty()) {
-            int node = q.peek().first;
-            int parent = q.peek().second;
-            q.remove();
+        Queue<Node> q = new LinkedList<>();
+        q.add(new Node(src, -1));
 
-            for (int adjacentNode : adj.get(node)) {
-                if (!vis[adjacentNode]) {
-                    vis[adjacentNode] = true;
-                    q.add(new Pair(adjacentNode, node));
+        while(!q.isEmpty()){
+            Node cur = q.poll();
+            int u = cur.node;
+            int par = cur.parent;
+
+            for(int v : adj.get(u)){
+                if(!visited[v]){
+                    visited[v] = true;
+                    q.add(new Node(v, u));
                 }
-
-                // everything except this 'else if' statement is normal BFS
-                else if (adjacentNode != parent) {
-                    return true; // cycle detected
+                else if(v != par){
+                    return true;   // cycle
                 }
             }
         }
         return false;
     }
 
-    public static boolean isCycle(int V, ArrayList<ArrayList<Integer>> adj) {
+    public static boolean isCycle(int V, ArrayList<ArrayList<Integer>> adj){
 
-        boolean[] vis = new boolean[V];
+        boolean visited[] = new boolean[V];
 
-        for (int i = 0; i < V; i++) {
-            if (!vis[i]) {
-                if (bfs(i, V, adj, vis)) {
-                    return true;
-                }
+        for(int i=0;i<V;i++){
+            if(!visited[i]){
+                if(bfs(i, V, adj, visited)) return true;
             }
         }
         return false;
     }
 
-    public static void main(String[] args) {
+
+    // ================= DRIVER =================
+    public static void main(String args[]){
 
         int V = 5;
         ArrayList<ArrayList<Integer>> adj = new ArrayList<>();
 
-        for (int i = 0; i < V; i++) {
-            adj.add(new ArrayList<>());
-        }
+        for(int i=0;i<V;i++) adj.add(new ArrayList<>());
 
-        // Undirected graph edges
+        // Undirected graph
         adj.get(0).add(1);
         adj.get(1).add(0);
 
@@ -71,12 +72,12 @@ public class CycleDetectionBFS {
         adj.get(2).add(3);
         adj.get(3).add(2);
 
-        adj.get(3).add(1); // creates a cycle
+        adj.get(3).add(1);
         adj.get(1).add(3);
 
         adj.get(3).add(4);
         adj.get(4).add(3);
 
-        System.out.printf(isCycle(V, adj) ? "Cycle detected" : "No cycle detected");
+        System.out.printf(isCycle(V, adj) ? "Cycle detected\n" : "No cycle detected\n");
     }
 }
diff --git a/Graphs/CycleDetectionDFS.java b/Graphs/CycleDetectionDFS.java
index 722df8e..5cebfc2 100644
--- a/Graphs/CycleDetectionDFS.java
+++ b/Graphs/CycleDetectionDFS.java
@@ -1,64 +1,60 @@
 import java.util.*;
+import java.io.*;
 
-public class CycleDetectionDFS {
+class Main {
 
-    static class Pair {
+    // helper structure
+    static class Node{
         int node;
         int parent;
 
-        Pair(int node, int parent) {
+        Node(int node, int parent){
             this.node = node;
             this.parent = parent;
         }
     }
 
-    public static boolean dfs(Pair current, boolean[] vis, ArrayList<ArrayList<Integer>> adj) {
+    public static boolean dfs(Node cur, boolean visited[],
+                              ArrayList<ArrayList<Integer>> adj){
 
-        int node = current.node;
-        int parent = current.parent;
+        int u = cur.node;
+        int par = cur.parent;
 
-        vis[node] = true;
+        visited[u] = true;
 
-        for (int adjacentNode : adj.get(node)) {
-
-            if (!vis[adjacentNode]) {
-                if (dfs(new Pair(adjacentNode, node), vis, adj)) {
-                    return true;
-                }
+        for(int v : adj.get(u)){
+            if(!visited[v]){
+                if(dfs(new Node(v, u), visited, adj)) return true;
             }
-
-            // everything except this 'else if' statement is normal DFS
-            else if (adjacentNode != parent) {
-                return true;
+            else if(v != par){
+                return true;   // cycle
             }
         }
         return false;
     }
 
-    public static boolean isCycle(int V, ArrayList<ArrayList<Integer>> adj) {
+    public static boolean isCycle(int V, ArrayList<ArrayList<Integer>> adj){
 
-        boolean[] vis = new boolean[V];
+        boolean visited[] = new boolean[V];
 
-        for (int i = 0; i < V; i++) {
-            if (!vis[i]) {
-                if (dfs(new Pair(i, -1), vis, adj)) {
-                    return true;
-                }
+        for(int i=0;i<V;i++){
+            if(!visited[i]){
+                if(dfs(new Node(i, -1), visited, adj)) return true;
             }
         }
         return false;
     }
 
-    public static void main(String[] args) {
+
+    // ================= DRIVER =================
+    public static void main(String args[]){
 
         int V = 5;
         ArrayList<ArrayList<Integer>> adj = new ArrayList<>();
 
-        for (int i = 0; i < V; i++) {
-            adj.add(new ArrayList<>());
-        }
+        for(int i=0;i<V;i++) adj.add(new ArrayList<>());
 
-        // Undirected graph edges
+        // Undirected graph
         adj.get(0).add(1);
         adj.get(1).add(0);
 
@@ -68,12 +64,12 @@ public class CycleDetectionDFS {
         adj.get(2).add(3);
         adj.get(3).add(2);
 
-        adj.get(3).add(1); // creates a cycle
+        adj.get(3).add(1);
         adj.get(1).add(3);
 
         adj.get(3).add(4);
         adj.get(4).add(3);
 
-        System.out.printf(isCycle(V, adj) ? "Cycle detected" : "No cycle detected");
+        System.out.printf(isCycle(V, adj) ? "Cycle detected\n" : "No cycle detected\n");
     }
 }