Codility Answers 01

Here is my answer to Cod1l1ty training lesson 01.

TapeEquilibrium

function sumArr(array $a){
    $n = count($a);
    
    $sum = 0;
    for($i = 0; $i < $n; $i++){
        $sum += $a[$i];
    }
    
    return $sum;
}

function solution(array $a) {
    $n = count($a);
    
    if($n == 1){
        return $a[0];
    }
    
    $min = null;
    $p = 1;
    $sum1 = 0;
    $sum2 = sumArr($a);
    do{
        $sum1 += $a[$p - 1];
        $sum2 -= $a[$p - 1];
        $diff = abs($sum1 - $sum2);
        if($diff == 0){
            return 0;
        }elseif($min === null || $diff < $min){
            $min = $diff;
        }
        $p++;
    }while($p < $n);
    
    return $min;
}

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FrogJmp

function solution($x, $y, $d) {
    $dist = $y - $x;
    if($dist % $d >= 1){
        return ((int)($dist / $d) + 1);
    }else{
        return (int)($dist / $d);
    }
}

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PermMissingElem

function solution($a) {
    $tempArr = [];
    $missing = 1;
    $n = count($a);
    $lookAtTemp = false;
    for($i = 0; $i < $n; $i++){
        if($a[$i] == $missing){
            $missing++;
            $lookAtTemp = true;
        }else{
            $tempArr[$a[$i]] = 1;
        }
        
        while($missing < $n + 1 && $lookAtTemp){
            if(isset($tempArr[$missing])){
                $missing++;
            }else{
                $lookAtTemp = false;
            }
        }
    }
    
    return $missing;
}

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