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Longest Subarray with Given Sum (Positives) - Optimal Approach

Longest Subarray with Given Sum (Positives) - Optimal Approach

Algorithm Steps

  1. Given an array arr and a target sum k.
  2. Initialize variables: start = 0, curr_sum = 0, and max_len = 0.
  3. Traverse the array using a loop with index end:
  4. → Add arr[end] to curr_sum.
  5. → While curr_sum > k, subtract arr[start] from curr_sum and increment start.
  6. → If curr_sum == k, update max_len as max(max_len, end - start + 1).
  7. Return max_len as the result after the loop.

Find Longest Subarray with Given Sum (Positive Numbers) Code

Python
JavaScript
Java
C++
C
def longest_subarray_sum_k(arr, k):
    start = 0
    curr_sum = 0
    max_len = 0
    for end in range(len(arr)):
        curr_sum += arr[end]
        while curr_sum > k:
            curr_sum -= arr[start]
            start += 1
        if curr_sum == k:
            max_len = max(max_len, end - start + 1)
    return max_len

# Sample Input
arr = [1, 2, 3, 1, 1, 1, 1, 2]
k = 5
print("Longest Subarray Length:", longest_subarray_sum_k(arr, k))