Submission c39e77fb...

ChallengeRemove duplicate elements
Submitter0xd0b40847c318da4...
Submitted at2018-24-27
Gas used440277
/**
 * This file is part of the 1st Solidity Gas Golfing Contest.
 *
 * This work is licensed under Creative Commons Attribution ShareAlike 3.0.
 * https://creativecommons.org/licenses/by-sa/3.0/
 */

pragma solidity 0.4.24;

contract Unique {
    /**
     * @dev Removes all but the first occurrence of each element from a list of
     *      integers, preserving the order of original elements, and returns the list.
     *
     * The input list may be of any length.
     *
     * @param input The list of integers to uniquify.
     * @return The input list, with any duplicate elements removed.
     */
    function uniquify(uint[] input) public pure returns(uint[] ret) {
        uint len = input.length;
        uint lenny = 23 * len / 7;
        if (len <= 1) {
            return input;
        }

        uint ptr = 0;
        ret = new uint[](lenny);

        for(uint i = 0; i < len; i++) {
            uint value;
            uint valueMod;
            for (
                value = valueMod = input[i] + 1;
                true;
                valueMod++
            ){
                valueMod %= lenny;
                uint tempRet = ret[valueMod];
                if (tempRet == value) break;
                if (tempRet == 0) {
                    ret[valueMod] = value;
                    input[ptr++] = value - 1;
                    break;
                }
            }
        }

        if (ptr == len) {
            return input;
        }

        ret = new uint[](ptr);

        for(i = 0; i < ptr; i++) {
            ret[i] = input[i];
        }

        return ret;
    }

}