COMPE course project

I have a C coding project for my computer engineering course and would like some help. I'm attempting to make a three-player connect 4 game that checks the board vertically, horizontally, and diagonally to see if any of the players have one. Right now, I have the board to print, accept user input, and loop the board, but the turn of the players is not updating, and their game pieces are not stored on the board.