remove function

Heap/Createheap.java

@@ -12,16 +12,68 @@ public void add(int data){
             int x=arr.size()-1;//x is child index
             int par=(x-1)/2;//par index
 
-            while(arr.get(x)<arr.get(x)){
+            while(arr.get(x)<arr.get(par)){
                 //swap
                 int temp=arr.get(x);
                 arr.set(x,arr.get(par));
                 arr.set(par,temp);
+                x=par;
+                par=(x-1)/2;
             }
         }
         public int peek(){
             return arr.get(0);
         }
+        private void heapify(int i){
+            int left=2*i+1;
+            int right = 2*i+2;
+            int minIdx=i;
+
+            if(left<arr.size() && arr.get(minIdx)>arr.get(left)){
+                minIdx=left;
+            }
+            if(right<arr.size() && arr.get(minIdx)>arr.get(right)){
+                minIdx=right;
+            }
+            if(minIdx!=i){
+                //swap
+                int temp=arr.get(i);
+                arr.set(i,arr.get(minIdx));
+                arr.set(minIdx,temp);
+                heapify(minIdx);
+            }
+
+        }
+        public  int remove(){
+            int data=arr.get(0);
+
+            int temp=arr.get(0);
+            arr.set(0,arr.get(arr.size()-1));
+            arr.set(arr.size()-1,temp);
+
+            arr.remove(arr.size()-1);
+
+            heapify(0);
+            return data;
+        }
+        public boolean isEmpty(){
+            return arr.size()==0;
+        }
+    }
+
+    public static void main(String[] args) {
+        Heap h=new Heap();
+        h.add(4);
+        h.add(3);
+
+        h.add(1);
+        h.add(5);
+
+
+        while(!h.isEmpty()){
+            System.out.println(h.peek());
+            h.remove();
+        }
     }
 
 }