Sliding Window: Dynamic

def find_all_subarrays(nums, target):
    """
    Finds and prints all contiguous subarrays whose sum equals the target.
    Assumes that all numbers in 'nums' are positive.
    """
    print("Problem: Given an array of positive integers and a target sum,")
    print("find all contiguous subarrays whose sum equals the target.\n")
    print(f"Example: nums = {nums}, target = {target}\n")
    print("-" * 70)
    
    left = 0
    current_sum = 0
    n = len(nums)
    
    # Iterate with 'right' pointer to expand the window.
    for right in range(n):
        current_sum += nums[right]
        print(f"Expanding window: added nums[{right}] = {nums[right]}")
        print(f"Current window (indices [{left} to {right}]): {nums[left:right+1]}")
        print(f"Current sum: {current_sum}\n")
        
        # If the sum exceeds the target, contract the window from the left.
        while current_sum > target and left <= right:
            print(f"  Sum {current_sum} exceeds target {target}.")
            print(f"  Removing nums[{left}] = {nums[left]} from window.")
            current_sum -= nums[left]
            left += 1
            print(f"  After contraction, window (indices [{left} to {right}]): {nums[left:right+1]}")
            print(f"  Current sum: {current_sum}\n")
        
        # If the current sum equals the target, print the subarray.
        if current_sum == target:
            print(f"Found subarray with sum {target}: indices [{left}, {right}] -> {nums[left:right+1]}\n")
    
    print("-" * 70)
    print("Done searching for subarrays.")

# Example usage:
nums = [1, 3, 2, 5, 1, 1, 2, 1, 4]
target = 8
find_all_subarrays(nums, target)