## Description In the `selectWinner` function, when a player has refunded and their address is replaced with address(0), the prize money may be sent to address(0), resulting in fund loss. ## Vulnerability Details In the `refund` function if a user wants to refund his money then he will be given his money back and his address in the array will be replaced with `address(0)`. So lets say `Alice` entered in the raffle and later decided to refund her money then her address in the `player` array will be replaced with `address(0)`. And lets consider that her index in the array is `7th` so currently there is `address(0)` at `7th index`, so when `selectWinner` function will be called there isn't any kind of check that this 7th index can't be the winner so if this `7th` index will be declared as winner then all the prize will be sent to him which will actually lost as it will be sent to `address(0)` ## Impact Loss of funds if they are sent to address(0), posing a financial risk. ## Recommendations Implement additional checks in the `selectWinner` function to ensure that prize money is not sent to `address(0)`