Smart Contract Error : Gas required exceeds 300000000

Question

I got the following code from this tutorial :

https://medium.com/@merunasgrincalaitis/the-ultimate-end-to-end-tutorial-to-create-and-deploy-a-fully-descentralized-dapp-in-ethereum-18f0cf6d7e0e

pragma solidity ^0.4.11;

contract Casino {


    uint minimumBet;
    uint totalBet;
    uint numberOfBets;
    uint maximumAmountsOfBets = 100;
    address[] players;

    struct Player {

        uint amountBet;
        uint numberSelected;
    }


    mapping(address => Player) playerInfo;


    address owner; // Long string from metamask


    function Casino(uint _minimumBet) public{  // Constructor : has the same name as the contract , used to set up
        //contract owner

        owner = msg.sender;
        if(_minimumBet !=0) minimumBet = _minimumBet;

        }

        //To be for a number btw 1 & 10 both inclusive


    function bet(uint number) payable public {

        require(checkPlayerExists(msg.sender) );
        require(number >= 1 && number <= 10);
        require(msg.value >= minimumBet);


        playerInfo[msg.sender].amountBet = msg.value;
        playerInfo[msg.sender].numberSelected = number;
        numberOfBets += 1;
        players.push(msg.sender);
        totalBet += msg.value;

        if(numberOfBets >= maximumAmountsOfBets) generateNumberWinner();


        }



    function checkPlayerExists(address player) public view returns(bool) {

        for( uint i = 0 ; i < players.length; i++){
            if(players[i] == player) return true;
        }
        return false;
    }


    /* 
    Generate Winner : Generates a number between 1 & 10 
    */

    function generateNumberWinner() public{

        uint numberGenerated = block.number % 10 + 1; // This isnt secure

        distributePrizes(numberGenerated);
    }


    /*

    Distribute Prizes : Sends the correspondng ether to each winner
    depending on the total bets 
    */

    function distributePrizes(uint numberWinner) public {

        address[100] memory winners ; // We have to create a temporary in memory array with fixed size

        uint count = 0; // This is the count for the array of winners

        for(uint i = 0; i < players.length ; i++) {
            address playerAddress = players[i];
            if(playerInfo[playerAddress].numberSelected == numberWinner){
                winners[count] = playerAddress;
                count ++;
            }
            delete playerInfo[playerAddress]; // Delete all the players array


        }

        players.length = 0; //Delete all the players array

        uint winnerEtherAmount = totalBet / winners.length; // How much each player gets 

        for(uint j = 0; j < count; j++) {

            if(winners[j] !=address(0)) // Check the address in the fixed array is not empty
            winners[j].transfer(winnerEtherAmount);
        }


    }

    /*
    Annonymous Fallback function: In case someone sends ether to the 
    contract so it doesnt get lost
    */
    function() payable private{}

/*
Kill function: Used to destroy contract whenever we want. Only owner
has the ability to kill the contract
*/

    function kill() private{ 

        if(msg.sender == owner)
            selfdestruct(owner);
    }
}

It compiles fine, but when I try to bet it REMIX throws the following error:

transact to Casino.bet errored: Gas required exceeded limits : 3000000. An important gas estimation may also be a sign of a problem in the contract code. Please check loops and be sure you did not sent value to a non payable function (that's also a reason for a strong gas estimation).

I would appreciate it if someone could point me in the right direction.

Answer 1

I believe that this line:

require(checkPlayerExists(msg.sender));

should actually say the opposite:

require(!checkPlayerExists(msg.sender));

The player can't possibly exist the first time they call bet, so that require is aborting the transaction.

Assuming you're following https://medium.com/@merunasgrincalaitis/the-ultimate-end-to-end-tutorial-to-create-and-deploy-a-fully-descentralized-dapp-in-ethereum-18f0cf6d7e0e, note that they have this line, which is roughly equivalent to what I suggested. (But I believe require is more appropriate here than assert.)

assert(checkPlayerExists(msg.sender) == false);