simple-voting-contract.sol

pragma solidity 0.4.24;

contract SimpleVoting {
    string public votingReason;
    uint256 public votesToEnd;

    mapping (address => bool) public alreadyVoted;

    uint256 public votesForTrue;
    uint256 public votesForFalse;

    bool public isEnded;

    constructor(string _votingReason, uint256 _votesToEnd) public {
        votingReason = _votingReason;
        votesToEnd = _votesToEnd;
    }

    function vote(bool _choice) public {
        require(alreadyVoted[msg.sender] != true, "Already voted");
        require(isEnded != true, "Voting ended");

        if(_choice == true) {
            votesForTrue += 1;
        } else {
            votesForFalse += 1;
        }

        if(votesForTrue >= votesToEnd || votesForFalse >= votesToEnd) {
            isEnded = true;
        }

        alreadyVoted[msg.sender] = true;
    }
}