Jack9

<?php
class Test {

    public $keyArr = array(
        "0","1","2","3","4","5","6","7","8","9",
        "A","B","C","D","E","F","G","H","I","J",
        "K","L","M","N","O","P","Q","R","S","T",
        "U","V","W"
    );
    public $keyArrSubset = array(
        "0","1","2","3","4","5","6","7","8","9"
    );

    public function Start($numChallenges ){
        //$numChallenges = 1000;
        //$challenges = $this->createChallenges($numChallenges);
        $challenges = $this->createInterestingChallenges($numChallenges);
        $this->solveChallenges($challenges);
        /*echo "---- TESTS BELOW ----<br/>\n";
        $tests = array(
            "1000 2000 3000", // 4
            "1111 1 10000", // 2
            "9F 1F B7", // 23
            "5 46 53", // 8
            "56 8 65", // 9
            "38 28 63", // 13
            "2 1 3", // 4
            "50 814 0864", // 9
            "7 16 22" // 11
            //"0 1 71799" // throw exception
        );
        $this->solveChallenges($tests);*/
    }

    public function solveChallenges($arr){
        foreach($arr as $setStr){
            $set = explode(" ",$setStr);
            $result = $this->determineBase($set[0],$set[1],$set[2]);
            if(!$result){
                //echo "No solution. - ".$setStr."<br/>\n";
            }else{
                echo "Valid Base: [".$result."] - Set:[".$setStr."]<br/>\n";
                $this->showMe($result,$setStr);
            }
        }
    }
    public function showMe($base, $setStr){
        $set = explode(" ",$setStr);
        echo base_convert($set[0],$base,10)." + ".base_convert($set[1],$base,10)." = ".base_convert($set[2],$base,10)."<br/>\n";
    }
    public function createChallenges($numChallenges){
        $challenges = array();
        for($challengeIndex=0;$challengeIndex<$numChallenges;$challengeIndex++){
            $a = $this->createRandStr(rand(1,20),$this->keyArr);
            $b = $this->createRandStr(rand(1,20),$this->keyArr);
            $c = $this->createRandStr(rand(1,20),$this->keyArr);
            //echo "Created: ".$a." ".$b." ".$c."<br/>\n";
            $challenges[$challengeIndex] = $a." ".$b." ".$c;
        }
        return $challenges;
    }

    public function createInterestingChallenges($numChallenges){
        $challenges = array();
        for($challengeIndex=0;$challengeIndex<$numChallenges;$challengeIndex++){
            $a = $this->createNotSoRandStr(rand(1,4),0,4);
            $b = $this->createNotSoRandStr(rand(1,4),0,4);
            $c = $this->createNotSoRandStr(rand(1,4),0,4);
            //echo "Created: ".$a." ".$b." ".$c."<br/>\n";
            $challenges[$challengeIndex] = $a." ".$b." ".$c;
        }
        return $challenges;
    }

    public function createNotSoRandStr($splitMe,$ratioTop,$ratioBot){
        $small = ceil($splitMe*$ratioTop/($ratioTop+$ratioBot));
        $large = floor($splitMe*$ratioBot/($ratioTop+$ratioBot));
        if($large < 1){
            $large = 1;
        }
        $randNum = "";
        if($small > 0){
            $randNum = $this->createRandStr($small,$this->keyArr);
        }
        $randSubsetNum = $this->createRandStr($large,$this->keyArrSubset);
        $final = str_shuffle($randNum.$randSubsetNum);
        if(base_convert($final,32,10) < 1){
            $final = $this->createNotSoRandStr($splitMe,$ratioTop,$ratioBot);
        }
        return $final;
    }

    public function createRandStr($num,$arr){
        $randStr = '';
        for($i=0;$i<$num;$i++){
            $rand = rand(0 , count($arr)-1);
            $randStr .= $arr[$rand];
        }
        if(base_convert($randStr,32,10) < 1){
            $randStr = $this->createRandStr($num,$arr);
        }
        return $randStr;
    }

    public function determineBase($a,$b,$c){
        if(!(is_string($a) && is_string($b) && is_string($c)) ||
           !(base_convert($a,35,10) > 0 && base_convert($b,35,10) > 0 && base_convert($c,35,10) > 0)
        ){
            throw new Exception("usage is determinBase(non-zero string,non-zero string,non-zero string):".$a." ".$b." ".$c);
        }

        if(strpbrk ($a.$b.$c,"XYZ") != ''){
            //echo "Cause: Base over 32 - ";
            return false;
        }

        $lowestBase = $this->lowestPossibleBase($a,$b,$c);
        if(!$lowestBase){
            //echo "Cause: Lowest base failure  - ";
            return false;
        }
        //echo "Possible bases between:".$lowestBase." and 32<br/>\n";
        $valid = false;
        for($i=$lowestBase;$i<=32;$i++){
            $baseTo10NumA = base_convert($a, $i, 10);
            $baseTo10NumB = base_convert($b, $i, 10);
            $baseTo10NumC = base_convert($c, $i, 10);
            //echo $i."<br/>\n";
            if($baseTo10NumA+$baseTo10NumB == $baseTo10NumC){
                $valid = $i;
                break;
            }
        }
        if(!$valid){
            //echo "Cause: Not valid for any base - ";
        }
        return $valid;
    }

    public function lowestPossibleBase($a,$b,$c){
        // Abuse the fact that array indexes are base10
        // And PHP SORT_REGULAR is awesome for mixed character values.
        $checkArr = array();
        $ABCarr = $a.$b.$c;
        for($i=0;$i<strlen($ABCarr);$i++){
            $key = array_search($ABCarr[$i], $this->keyArr);
            $checkArr[$this->keyArr[$key]] = $ABCarr[$i];
        }
        rsort($checkArr,SORT_REGULAR);
        $key = array_search($checkArr[0], $this->keyArr);
        if($key > 0 && $key < 32){
            return $key+1;
        }
        return false;
    }
} // DONE
$t = new Test();
$t->Start(1000);