Teemo attacks an enemy, applying poison for a certain duration. Given the times of Teemo's attacks, calculate the total time the enemy is poisoned.

Fill in the empty cells of a partially completed Sudoku grid according to the game's rules. The goal is to complete the grid so that each row, column, and 3x3 subgrid contains all digits from 1 to 9 without repetition.

Determine if a given 9x9 Sudoku board is valid. Check if each row, column, and 3x3 subgrid contains the digits 1-9 without repetition.