Final answer:
The program should check all possible winning combinations on the 4x4x4 3D Tic-Tac-Toe board and determine the winner.
Step-by-step explanation:
The problem can be solved by checking all possible winning combinations in each direction (vertical, horizontal, diagonal, and 3D diagonal) on the 4x4x4 board. This can be done by iterating through each cell and checking if there is a winning combination starting from that cell. The program should keep track of the player who has formed four in a row and mark the winning cells with capital X or O. If no player has won, the program should print 'no winner'.