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hadcoin_ico.sol

pragma solidity ^0.4.11;

contract hadcoin_ico{
    
    // Introducing the total number of hadcoin tokens available for sealed
    uint public max_hadcoins = 1000000;
    
    // Introducing the USD to hadcoin conversion rate 
    uint public usd_to_hadcoins = 1000;
    
    // Introducing the total number of hadcoins that have been bought by the investors
    uint public total_hadcoins_bought = 0;
    
    // Mapping from the investor address to its equity in hadcoins and USD
    mapping(address => uint) equity_hadcoins;
    mapping(address => uint) equity_usd;
    
    // Checking if an investor can buy Hadcoins 
    modifier can_buy_hadcoins(uint usd_invested) {
        require(usd_invested * usd_to_hadcoins + total_hadcoins_bought <= max_hadcoins);
        _;
    }
    
    // Getting the equity in Hadcoins of an investor
    function equity_in_hadcoins(address investor) external constant returns(uint){
        return equity_hadcoins[investor];
    }
    
    
    // Getting the equity in USD of an investor
       function equity_in_usd(address investor) external constant returns(uint){
        return equity_usd[investor];
    }
    
    //Buy Hadcoins
    function buy_hadcoins(address investor ,uint usd_invested) external
     can_buy_hadcoins(usd_invested)
    {
       uint hadcoins_bought = usd_invested * usd_to_hadcoins;
        equity_hadcoins[investor] += hadcoins_bought;
        equity_usd[investor] =  equity_hadcoins[investor] / 1000;
        total_hadcoins_bought += hadcoins_bought;
    }
    
    // Selling Hadcoin 
    function sell_hadcoins(address investor,uint hadcoins_sold) external{
        equity_hadcoins[investor] -= hadcoins_sold;
        equity_usd[investor] =  equity_hadcoins[investor] / 1000;
        total_hadcoins_bought -= hadcoins_sold;
    }
    
    
}