#include <stdio.h>
/*
Demonstration of traversing an array from both sides at the same time
in idiomatic C.
We use the classic "two-pointer" technique:
- left starts at index 0
- right starts at index n - 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: traverse_from_both_sides
// Purpose: Traverse an array from both ends simultaneously.
// ------------------------------------------------------------
void traverse_from_both_sides(const int *arr, int n) {
int left = 0;
int right = n - 1;
// Move inward until the pointers cross
while (left <= right) {
printf("Left: %d, Right: %d\n", arr[left], arr[right]);
left++;
right--;
}
}
// ------------------------------------------------------------
// Main program
// ------------------------------------------------------------
int main(void)
{
int data[] = {10, 20, 30, 40, 50, 60, 70, 80, 90};
int n = sizeof(data) / sizeof(data[0]);
printf("Traversing from both sides:\n");
traverse_from_both_sides(data, n);
return 0;
}
/*
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
*/
