feat: Find largest and second largest elements in array

🧠 Logic:
- Initialize `max1` and `max2` with the first element of the array.
- Traverse the array:
  - If current element > `max1`, update `max2 = max1` and `max1 = current element`.
  - Else if current element > `max2`, update `max2 = current element`.
- Added a check for arrays with less than 2 elements (though placed inside the loop — logically should be outside).
- Print the largest and second largest elements.

Signed-off-by: Somesh diwan <[email protected]>

Author: Someshdiwan

Section9ArrayAB/Array IMP/LargestElementArray.java

@@ -1,29 +1,22 @@
 import java.util.Scanner;
 
-public class LargestElementArray
-{
-    public static void main(String[] args)
-    {
+public class LargestElementArray {
+    public static void main(String[] args) {
         int A[]={3,9,7,8,12,6,15,5,4,10,1};
 
         int max1,max2;
 
-        max1=max2=A[0];
+        max1=max2=A[0]; //initialize the 1st element in the array.
 
-        for(int i=0; i<A.length; i++)
-        {
-            if(A[i]>max1)
-            {
+        for(int i=0; i<A.length; i++) {
+            if(A[i]>max1) {
                 max2=max1;
                 max1=A[i];
             }
-            else if (A[i]>max2)
-            {
+            else if (A[i]>max2) {
                 max2=A[i];
             }
-
-            if (A.length < 2)
-            {
+            if (A.length < 2) {
                 System.out.println("Array must have at least two elements.");
                 return;
             }
@@ -33,23 +26,48 @@ else if (A[i]>max2)
     }
 }
 
+/*
+A swapping pattern that's commonly used when tracking two maximum values.
+
+1. First line: The current maximum value () becomes the second maximum () `max2=max1;``max1``max2`
+2. Second line: The new largest value from the array () becomes the new maximum () `max1=A[i];``A[i]``max1`
+
+This is a typical technique when you need to keep track of both the largest and second-largest values.
+
+When a new maximum is found, the old maximum doesn't just get discarded - it becomes the second maximum.
+
+For example,
+
+If:
+- was 10 `max1`
+- was 8 `max2`
+- And we find is 15 `A[i]`
+
+The execution would go:
+1. → becomes 10 `max2 = max1``max2`
+2. → becomes 15 `max1 = A[i]``max1`
+*/
+
 /*
 Time Complexity
-Initialization:
 
+Initialization:
 Assignments for max1 and max2: O(1).
+
 Loop through the array (for loop):
 
 The program iterates through the array exactly once.
+
 In each iteration, it performs a constant amount of work (comparison and assignment).
+
 Time complexity of this loop: O(n), where n is the size of the array.
 Thus, the overall time complexity is O(n).
 
 Space Complexity
 The space used by the program includes:
+
 The input array A[]: O(n), where n is the number of elements in the array.
 Variables max1 and max2: O(1) (constant space).
 Other local variables (like i in the loop): O(1).
 The program does not use any extra data structures; it operates directly on the input array.
-
-*/
+*/