# Problem Description
This is an array comparison problem where we need to:
1. Subtract two arrays element by element (arr1[i] - arr2[i])
2. Compare each result against a threshold t, where t = len(arr1)
3. Count the number of valid elements (Nvalid) where the subtraction result is greater than t
4. The arrays arr1 and arr2 must have the same length

# Visual Facts
1. The image shows 3 different examples of array comparisons:
   - Example 1: 6 elements in each array, Nvalid = 2
   - Example 2: 2 elements in each array, Nvalid = 0
   - Example 3: 7 elements in each array, Nvalid = 3

2. Each example shows:
   - Left array (arr1) in orange
   - Middle array (arr2) in green
   - Result array after subtraction in right column
   - Color coding in result: pink (≤t) and green (>t)
   - Value t = len(arr1) shown for each case

3. The threshold t equals the length of arr1 in each case:
   - Example 1: t = 6
   - Example 2: t = 2
   - Example 3: t = 7

# Visual Patterns
1. Calculation Pattern:
   - For each position i: result[i] = arr1[i] - arr2[i]
   - The result is compared against t = len(arr1)
   - Valid elements are those where result[i] > t


# Solution
def solution(arr1: list[int], arr2: list[int]) -> int:
    """
    Counts the number of valid elements by comparing two integer arrays according to the specified rules.

    Parameters:
        arr1 (list[int]): The first integer array
        arr2 (list[int]): The second integer array

    Returns:
        int: The count of valid elements
    """
    threshold = len(arr1)
    return [arr1[i]-arr2[i]>threshold for i in range(threshold)].count(True)


# Test Script
def test():
    test_cases = [
        ([2,9,5,9,-6,3],[3,-1,0,1,-7,6], 2),
        ([2,1],[1,-1], 0),
        ([6,7,-3,8,2,-3,4],[4,-1,0,-2,-7,-4,-3], 3),
        ([5, 4, 5, 10, 7, 4, 5, 9, 2, 6], [8, 5, 4, 10, 10, 10, 8, 5, 7, 10], 0),
        ([8, 4, 9, 10, 4, 0, 3], [0, 4, 5, 9, 10, 7, 5], 1),
        ([0, 0, 5, 3, 2, 0, 5, 6, 0], [8, 2, 9, 0, 6, 6, 4, 5, 8], 0),
        ([1, 2, 4, 5, 4, 6, 4], [2, 10, 1, 2, 6, 3, 6], 0),
        ([2],[2], 0),
        ([8, 5, 7, 4, 1, 6, 0, 4, 3, 6],[-100, 6, 5, 10, 4, 3, 2, 9, 10, 3], 1),
        ([4, 6],[6, 1], 1),
    ]

    for arr1, arr2, expected_output in test_cases:
        try:
            output = solution(arr1, arr2)
        except Exception as e:
            error_message = (
                f"An exception occurred while running the test case:\n"
                f"`arr1`: {arr1}\n"
                f"`arr2`: {arr2}\n\n"
                f"Exception: '{str(e)}'"
            )
            assert False, error_message

        if output != expected_output:
            error_message = (
                f"The following Test Case failed:\n"
                f"`arr1`: {arr1}\n" 
                f"`arr2`: {arr2}\n\n"
                f"Actual Output: {output}\n"
                f"Expected Output: {expected_output}"
            )
            assert False, error_message

test()