How do I make a random levels system?

In my game I have 25 levels, and I need that when the player clicks play, it enters some random level. But if he dies, and returns to the menu, and clicks play again, the level he has played can not be chosen again. Could anyone help me how to make this system random. Note: If the player leaves the game everything returns to normal, they are not saved the phases that he played.

See the solution given here () for non repeating random numbers. Arrays are global, so even when you change layouts it will keep track of the levels you do not want repeated.

Thank you.