Hi Dodoro,
Welcome to the Forum.
"German election stalemate leaves parties jostling for power"
"stalemate leaves",what does this words mean?
A stalemate means a situation between two people or groups in which neither can win and neither can lose. For example, this sometimes happens in a game of chess.
One meaning of 'to leave' is to give a result. For example, the rain left me wet.
Your sentence means this. In the German election, no party won. The result is that the parties are still struggling ('jostling') with each other for power.
Best wishes, Clive