Question: 1. Describe the directed graph whose adjacency matrix has all 0s on the main diagonal and 1s everywhere else.
2. Describe the directed graph whose adjacency matrix has all 1s in row 1 and column 1, and 0s elsewhere.
3. Describe the directed graph whose adjacency matrix has 1s in positions (i, i + 1) for 1 ≤ i ≤ n - 1, a 1 in position (n, 1), and 0s elsewhere.