public class TraverseBothSides {
/**
Demonstration of traversing an array from both sides at the same time
in idiomatic Java.
We use the classic "two‑index" technique:
- left starts at index 0
- right starts at index array.length - 1
Both move toward the center.
This approach is efficient (O(n)), simple, and widely used in
algorithms such as palindrome checks, partitioning, and pair searching.
*/
// ------------------------------------------------------------
// Function: traverseFromBothSides
// Purpose: Traverse an array from both ends simultaneously.
// ------------------------------------------------------------
public static void traverseFromBothSides(int[] arr) {
int left = 0;
int right = arr.length - 1;
// Move inward until the indices cross
while (left <= right) {
System.out.println("Left: " + arr[left] + ", Right: " + arr[right]);
left++;
right--;
}
}
// ------------------------------------------------------------
// Main program
// ------------------------------------------------------------
public static void main(String[] args) {
int[] array = {10, 20, 30, 40, 50, 60, 70, 80, 90};
System.out.println("Traversing from both sides:");
traverseFromBothSides(array);
}
}
/*
run:
Traversing from both sides:
Left: 10, Right: 90
Left: 20, Right: 80
Left: 30, Right: 70
Left: 40, Right: 60
Left: 50, Right: 50
*/
