Dynamic Dispatch in Java (OOP concept)

LeetCode/Subarray Sum Divisible by K.java

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+class Solution {
+    public int subarraysDivByK(int[] nums, int k) {
+        int count =0;
+        int sum =0;
+        int rem =0;
+        HashMap<Integer,Integer> map = new HashMap<>();
+        map.put(0,1); //initially sum is 0 and it appeared once already
+
+        for(int num:nums){
+            sum+=num;
+            rem=sum%k;
+
+            if(rem<0){
+                rem+=k; // if k=7 and rem = -2 then rem+k =2 and the gap betwen 2 and -5 is 7 which is divisible by 7
+            }
+            if(map.containsKey(rem)){
+                count+=map.get(rem);
+                map.put(rem, map.get(rem)+1);
+            }
+            else{
+                map.put(rem,1);
+            }
+        }
+        System.out.println(map.entrySet());
+        return count;
+    }
+}

OOP concepts/DynamicDispatch.java

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+class Parent
+{
+	void disp()
+	{
+		System.out.println("I am disp method from Parent's class");
+	}
+}
+class Ankit extends Parent
+{
+	void disp()
+	{
+		System.out.println("I am disp method from Ankit's class");
+	}
+}
+class Gautam extends Parent
+{
+	void disp()
+	{
+		System.out.println("I am disp method from gautam's class");
+	}
+}
+class Dynamic
+{
+	public static void main(String [] args)
+	{
+		Parent p = new Parent();
+		Ankit a = new Ankit();
+		Gautam g = new Gautam();
+		Parent ref;
+		ref = a;
+		ref.disp();
+		ref =g;
+		ref.disp();
+	}
+}