iOSLearner-dev · August 13, 2018 09:40 · Aug 13, 2018
diff --git a/ballot.sol b/ballot.sol
@@ -0,0 +1,65 @@
+pragma solidity ^0.4.0;
+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.
+    function Ballot(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 constant 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;
+            }
+    }
+}
diff --git a/ballot_test.sol b/ballot_test.sol
@@ -0,0 +1,20 @@
+pragma solidity ^0.4.7;
+import "remix_tests.sol"; // this import is automatically injected by Remix.
+import "./ballot.sol";
+
+contract test3 {
+
+    Ballot ballotToTest;
+    function beforeAll () {
+       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 constant returns (bool) {
+        return ballotToTest.winningProposal() == 1;
+    }
+}