Rub3nC · March 22, 2019 00:17 · Mar 22, 2019
diff --git a/Array.sol b/Array.sol
@@ -0,0 +1,30 @@
+pragma solidity >=0.4.22 <0.7.0;
+
+
+contract myArray {
+    function getArraySum(uint[] memory _array) public pure returns (uint sum_) {
+        sum_ = 0;
+
+        for (uint i = 0; i < _array.length; i++) {
+            sum_ += _array[i];
+        }
+    }
+
+    function getArrayMultipliedByScalar(uint[] memory _array, uint scalar) public pure returns (uint[] memory outputArray) {
+        outputArray = new uint[](_array.length);
+
+        for (uint i = 0; i < _array.length; i++) {
+            outputArray[i] = _array[i] * scalar;
+        }
+    }
+
+
+    function getFixedArrayMultipliedByScalar(uint[3] memory _array, uint scalar) public pure returns (uint[] memory outputArray) {
+        assert(_array.length == 3);
+
+        outputArray = new uint[](_array.length);
+        for (uint i = 0; i < _array.length; i++) {
+            outputArray[i] = _array[i] * scalar;
+        }
+    }
+}
diff --git a/Ballot.sol b/Ballot.sol
@@ -0,0 +1,150 @@
+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;
+    }
+}
diff --git a/Coin.sol b/Coin.sol
@@ -0,0 +1,31 @@
+pragma solidity >=0.5.0 <0.7.0;
+
+contract Coin {
+    // The keyword "public" makes those variables
+    // easily readable from outside.
+    address public minter;
+    mapping (address => uint) public balances;
+
+    // Events allow light clients to react to
+    // changes efficiently.
+    event Sent(address from, address to, uint amount);
+
+    // This is the constructor whose code is
+    // run only when the contract is created.
+    constructor() public {
+        minter = msg.sender;
+    }
+
+    function mint(address receiver, uint amount) public {
+        require(msg.sender == minter);
+        require(amount < 1e60);
+        balances[receiver] += amount;
+    }
+
+    function send(address receiver, uint amount) public {
+        require(amount <= balances[msg.sender], "Insufficient balance.");
+        balances[msg.sender] -= amount;
+        balances[receiver] += amount;
+        emit Sent(msg.sender, receiver, amount);
+    }
+}
diff --git a/Storage.sol b/Storage.sol
@@ -0,0 +1,22 @@
+pragma solidity >=0.4.0 <0.7.0;
+
+contract SimpleStorage {
+    uint storedData;
+    uint myNumber;
+
+    function setNumber(uint x) public {
+        myNumber = x;    
+    }
+
+    function set(uint y) public {
+        storedData = y;
+    }
+
+    function get() public view returns (uint) {
+        return storedData;
+    }
+
+    function getNumber() public view returns (uint) {
+        return myNumber;
+    }
+}
diff --git a/Strings.sol b/Strings.sol
@@ -0,0 +1,27 @@
+pragma solidity >=0.4.22 <0.7.0;
+
+
+ view returns (string memory) {
+        return store;
+    } 
+
+    function setStore(string memory _value) public {
+        store = _value;
+    }
+
+    function createString() public pure returns (string memory) {
+        string memory newString = new string(3);
+        bytes memory byteString = bytes(newString);
+
+        byteString[0] = "A";
+        byteString[1] = "b";
+        byteString[2] = "X";
+
+        return string(byteString);
+    }
+
+    function getStringLength(string memory _s) public pure returns (uint) {
+        bytes memory bs = bytes(_s);
+        return bs.length;
+    }
+}
diff --git a/uBloggerRegistry.sol b/uBloggerRegistry.sol
@@ -0,0 +1,36 @@
+pragma solidity >=0.4.22 <0.7.0;
+
+
+contract uBloggerRegistry {
+    mapping(address => string) public address2Name;
+    mapping(string => address) public name2Address;
+
+
+    function registerAccount(string memory accountName) public returns (int result){
+        // Check the length of the accountName
+        if ( bytes(accountName).length == 0 || bytes(accountName).length > 10) {
+           result = -1;
+        }
+
+        // Check if name is already taken
+        if (name2Address[accountName] != address(0) ) {
+            result = -2;
+        }
+
+        // Check if msg.sender already has a name registered
+        if (bytes(address2Name[msg.sender]).length != 0 ) {
+            result = -3;
+        }
+
+        // Everything is OK
+        if (result < 0) {
+            address2Name[msg.sender] = accountName;
+            name2Address[accountName] = msg.sender;
+            result = 0;
+        }
+   }
+
+    /*function getAccount(address _address) public view returns(string memory accountName) {
+        accountName = string(accounts[_address]);
+    }*/
+}