Synchronized Hiking

Two hikers, Alice and Bob, are walking parallel paths. We record their elevation gain/loss at every meter for N meters. Alice's changes are in array A, and Bob's are in array B. Count the number of intervals [i, j] where the total elevation change for Alice is exactly twice the total elevation change for Bob. Input Format: The first line contains N. The second line contains N integers for Alice's path A. The third line contains N integers for Bob's path B. Output Format: A single integer representing the count of intervals. Example: Input: 3 2 4 2 1 2 1 Output: 6 Explanation: Every subarray [i, j] satisfies sum(A[i..j]) = 2 * sum(B[i..j]). There are 6 such subarrays.