java/BFS: Prettify code

2 files changed, 95 insertions, 91 deletions

diff --git a/algorithms/java/BFS.java b/algorithms/java/BFS.java
new file mode 100644
index 0000000..477461c
--- /dev/null
+++ b/algorithms/java/BFS.java
@@ -0,0 +1,95 @@
+class Coordinates {
+    // for storing coordinates as object.
+    public int x, y;
+
+    Coordinates(int x,int y) {
+        this.x = x;
+        this.y = y;
+    }
+}
+
+public class BFS {
+    // queue of coordinates.
+    static Coordinates[] queue = new Coordinates[1000];
+    private static int front = -1;
+    private static int rear = -1;
+
+    static void enqueue(Coordinates coord) {
+        if (front == -1 && rear == -1) {
+            front = 0;
+            rear = 0;
+        } else {
+            rear++;
+        }
+        queue[rear] = coord;
+    }
+
+    static void dequeue() {
+        if (front == 0 && rear == 0) {
+            front = -1;
+            rear = -1;
+        } else {
+            front++;
+        }
+    }
+
+    // traversing directions.
+    private static final int[][] dir = new int[][]{
+        {+0, +1}, // right.
+        {+1, +0}, // down.
+        {+0, -1}, // left.
+        {-1, +0}, // up.
+    };
+
+    static void bfs(char[][] maze, Coordinates start, boolean[][] visited) {
+        int curx;
+        int cury;
+        for (int i = 0; i < 4; i++) {
+            curx = start.x;
+            cury = start.y;
+
+            curx += dir[i][0];
+            cury += dir[i][1];
+
+            if (curx < 0 || cury < 0 || curx > maze.length - 1 || cury > maze.length - 1) {
+                // for square...  out of maze check.
+                continue;
+            } else if (maze[curx][cury] == '$') {
+                System.out.println("Path found");
+                System.exit(0);
+            } else if (visited[curx][cury] || maze[curx][cury] == '#') {
+                continue;
+            } else if(maze[curx][cury]=='_') {
+                enqueue(new Coordinates(curx, cury));
+                visited[curx][cury] = true;
+            }
+        }
+        dequeue();
+        if (front == -1) {
+            System.out.println("path not found");
+            System.exit(0);
+        } else
+            bfs(maze, queue[front], visited);
+    }
+
+    public static void main(String[] args) {
+        char[][] maze = {
+            {'*', '#', '#'},
+            {'_', '_', '#'},
+            {'_', '#', '$'},
+        };
+
+        Coordinates start = new Coordinates(0,0);
+        boolean[][] visited = new boolean[maze.length][maze.length];
+
+        for (int i = 0; i < maze.length; i++) {
+            for (int j = 0; j < maze.length; j++) {
+                visited[i][j] = false;
+            }
+        }
+
+        visited[0][0] = true;
+        enqueue(start);
+        bfs(maze, start, visited);
+    }
+}
diff --git a/algorithms/java/BFS.txt b/algorithms/java/BFS.txt
deleted file mode 100644
index d8eb925..0000000
--- a/algorithms/java/BFS.txt
+++ /dev/null
@@ -1,91 +0,0 @@
-package com.company;

-class Coordinates{

-    public int x,y;                 //for storing coordinates as object

-    Coordinates(int x,int y){

-        this.x=x;

-        this.y=y;

-    }

-}

-public class BFS {                      //BFS main class

-    static Coordinates[] queue=new Coordinates[1000];         //queue of coordinates

-    private static int front=-1;

-    private static int rear=-1;

-

-

-    static void enqueue(Coordinates coord){   //enqueue function

-        if(front==-1 && rear==-1){

-            front=0;

-            rear=0;

-        }

-        else{

-            rear++;

-        }

-        queue[rear]= coord;

-    }

-    static void dequeue(){              //dequeue operation

-        if(front==0 && rear==0){

-            front=-1;

-            rear=-1;

-        }

-        else{

-            front++;

-        }

-    }

-

-    private static final int[][] dir=new int[][]{       //traversing directions

-            {0,1}, //right

-            {1,0}, //down

-            {0,-1}, //left

-            {-1,0} //up

-    };

-

-    static void bfs(char[][] maze,Coordinates start,boolean[][] visited){

-        int curx;

-        int cury;

-        for(int i=0;i<4;i++){

-            curx=start.x;

-            cury=start.y;

-            curx+=dir[i][0];

-            cury+=dir[i][1];

-            if(curx<0 || cury<0 || curx> maze.length-1 || cury>maze.length-1){

-                continue;                                                           //for square...  out of maze check

-            }

-            else if(maze[curx][cury]=='$'){

-                System.out.println("Path found");

-                System.exit(0);

-            }

-            else if(visited[curx][cury] || maze[curx][cury]=='#'){

-                continue;

-            }

-            else if(maze[curx][cury]=='_'){

-                enqueue(new Coordinates(curx,cury));

-                visited[curx][cury]=true;

-            }

-        }

-        dequeue();

-        if(front==-1){

-            System.out.println("path not found");

-            System.exit(0);

-        }

-        else

-            bfs(maze,queue[front],visited);

-    }

-    public static void main(String[] args) {

-        char[][] maze = {{'*','#','#'},

-                         {'_','_','#'},

-                          {'_','#','$'},

-        };

-        Coordinates start=new Coordinates(0,0);

-        boolean[][] visited=new boolean[maze.length][maze.length];

-        for(int i=0;i< maze.length;i++){

-            for(int j=0;j<maze.length;j++)  {

-                visited[i][j]=false;

-            }

-        }

-        visited[0][0]=true;

-        enqueue(start);

-        bfs(maze,start,visited);

-    }

-}

-

-