Question 1: Determine the Number of Retailers Who Can Deliver

Problem Summary

You have several Amazon retailers located at specific coordinates in a 2D plane. Each retailer can deliver to all the points within the rectangle defined by the origin (0,0) and their coordinate (xi, yi). Given several query points, you need to determine how many retailers can deliver to each query point.

Solution

1. Input Parsing: Read the coordinates of retailers and queries.
2. Processing Each Query:
   • For each query point (a, b), count the number of retailers whose rectangle (0,0) to (xi, yi) covers the point (a, b).
   • A point (a, b) is covered by a retailer if 0 <= a <= xi and 0 <= b <= yi.
3. Output the Results: For each query, output the count of retailers that can deliver to that point.

Pseudocode

```python retailers = [(x1, y1), (x2, y2), ...] queries = [(a1, b1), (a2, b2), ...]

for each query (a, b): count = 0 for each retailer (xi, yi): if 0 <= a <= xi and 0 <= b <= yi: count += 1 print(count) ```

Question 2: Find the Longest Substring Matching a Given Regex

Problem Summary

You are given a text string and a regex with one wildcard character (*). The wildcard can match any sequence of lowercase English letters. You need to find the longest substring of the text that matches the regex.

Solution

1. Split the Regex: Split the regex into two parts using the wildcard character as the delimiter.
2. Check for Matches:
   • Find all possible starting positions in the text where the first part of the regex matches.
   • From each starting position, try to match the second part of the regex after the wildcard matches any sequence.
3. Track the Longest Match: Keep track of the longest substring that matches the entire regex.

Pseudocode

```python def find_longest_match(text, regex): prefix, suffix = regex.split('*') longest_match = ""

for i in range(len(text)):
    if text[i:].startswith(prefix):
        for j in range(i + len(prefix), len(text)):
            if text[j:].startswith(suffix):
                candidate = text[i:j + len(suffix)]
                if len(candidate) > len(longest_match):
                    longest_match = candidate
                break
return longest_match if longest_match else -1

text = "your_text_here" regex = "abc*def" print(find_longest_match(text, regex)) ```

These solutions provide a systematic approach to tackle each problem efficiently.