Codility Answers 04

Here is my answer to Cod1l1ty training lesson 04.

CountDiv

function solution($A) {
////  Brute-force way
//    $n = count($A);
//    $max = null;
//    for($p = 0; $p < $n - 2; $p++) {
//        for($q = $p + 1; $q < $n -1; $q++) {
//            for($r = $q + 1; $r < $n; $r++) {
//               $product = $A[$p] * $A[$q] * $A[$r];
//                if($max === null || $max < $product){
//                    $max = $product;
//                }
//            }
//        }
//    }
    
//  Better way
    $p = null;
    $q = null;
    $r = null;
    $p1 = null;
    $q1 = null;
    $r1 = null;
    
    foreach($A as $val){
        if($p === null || $val >= $p) {
            $r = $q;
            $q = $p;
            $p = $val;
        }elseif($q === null || $val >= $q) {
            $r = $q;
            $q = $val;
        }elseif($r === null || $val >= $r) {
            $r = $val;
        }
        if($p1 === null || $val <= $p1) {
            $r1 = $q1;
            $q1 = $p1;
            $p1 = $val;
        }elseif($q1 === null || $val <= $q1) {
            $r1 = $q1;
            $q1 = $val;
        }elseif($r1 === null || $val <= $r1) {
            $r1 = $val;
        }
    }
    
    if($p >= 0){
        if($r <= 0 || $p1 * $q1 > $q * $r) {
            $q = $p1;
            $r = $q1;
        }
    }
    
    return $p*$q*$r;
}

---

Should use merge sort for best performance, but because I didn't know how to do it yet, so I'll leave it like this for now.

Codility Answers 03

Here is my answer to Cod1l1ty training lesson 03.

CountDiv

function solution($a, $b, $k) {
    $i = ($a % $k == 0 ? $a : $a + ($k - ($a % $k)));
    
    $ret = 0;
    if ($i < $b) {
        $ret = (int)(($b - $i) / $k) + 1;
    }elseif($i == $a){
        $ret = 1;
    }
    
    return $ret;
}

---

PassingCars

function solution($A) {
    $n = count($A);
    $sum = [];
    $m = 0;
    for($i = 0; $i < $n; $i++) {
        if($A[$i] == 0) {
            $sum[] = 0;
            $m++;
        }elseif($m > 0){
            $sum[$m - 1]++;
        }
    }
    
    $sumTot = 0;
    for($i = 0; $i < $m; $i++) {
        $sumTot += ($sum[$i] + ($i * $sum[$i]));
        if($sumTot > 1000000000) {
            return -1;
        }
    }
    
    return $sumTot;
}

---

MinAvgTwoSlice

function solution($A) {
    $n = count($A);
    
    $idx = 0;
    $min = null;
    $sums = [$A[0]];
    for($p = 0; $p < $n - 1; $p++) {
        for($q = $p + 1; $q < $n; $q++) {
            $sums[$q] = $sums[$q - 1] + $A[$q];
            
            $avg = ($sums[$q] - $sums[$p] + $A[$p]) / ($q - $p + 1);
            if($avg < $min || $min === null) {
                $min = $avg;
                $idx = $p;
            }
        }
    }
    return $idx;
}

---

GenomicRangeQuery

function solution($S, $P, $Q) {
    $ret = [];
    $m = count($P);
    for($i = 0; $i < $m; $i++) {
        $min = '';

        for($j = $P[$i]; $j <= $Q[$i]; $j++) {
            if($min == '' || $min > $S[$j]) {
                $min = $S[$j];
            }
        }

        switch($min) {
            case 'A':
                $ret[] = 1;
                break;
            case 'C':
                $ret[] = 2;
                break;
            case 'G':
                $ret[] = 3;
                break;
            default:
                $ret[] = 4;
        }
    }
    
    return $ret;
}

---

Codility Answers 02

Here is my answer to Cod1l1ty training lesson 02.

FrogRiverOne

function solution($X, $A) {
    $c = count($A);
    $current = 0;
    $leaves = [];
    for($i = 0; $i < $c; $i++){
        if($current + 1 == $A[$i]){
            $current++;
        }
        while($current < $X){
            if(!isset($leaves[$current + 1])){
                break;
            }else{
                $current++;
            }
        }
        if($current >= $X){
            return $i;
        }
        
        $leaves[$A[$i]] = 1;
    }
    
    return -1;
}

---

PermCheck

function solution($a) {
    $tempArr = [];
    $n = count($a);
    
    for($i = 0; $i < $n; $i++){
        if($a[$i] > $n || isset($tempArr[$a[$i]])){
            return 0;
        }
        
        $tempArr[$a[$i]] = 1;
    }
        
    return 1;
}

---

MissingInteger

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;
}

---

MaxCounters

class ct{
    private $arr;
    private $ct;
    
    public function __construct($n){
        $this->ct = $n;
        for($i = 0; $i < $n; $i++){
            $this->arr[$i] = 0;
        }
    }
    
    public function increase($x){
        $this->arr[$x-1] += 1;
    }
    
    public function maxCounter(){
        $max = 0;
        foreach($this->arr as $val){
            $max = ($max < $val ? $val : $max);
        }
        for($i = 0; $i <= $this->ct; $i++){
            $this->arr[$i] = $max;
        }
    }
    
    public function getArr(){
        return $this->arr;
    }
}

function solution($n, $a) {
    $counter = new ct($n);
    
    foreach($a as $val){
        if($val >= 1 && $val <= $n){
            $counter->increase($val);
        }elseif($val == $n + 1){
            $counter->maxCounter();
        }
    }
    
    return $counter->getArr();
}

---

Cake Bank

Tutorial on how to use CakePHP to make the same banking that we do before. So far, it looks more simple that directly using PHP.

Here, I'll also show you how to setup Netbeans to use a remote server.



Sorry for the silence, I think without sound makes it faster :p

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;
}

---

FrogJmp

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

---

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;
}

---

Web Development Study - Creating a simple online banking

Hi all,

For this chance, I'll make an online banking site using XAMPP. All development process will be recorded without cuts so you can see step by step of this tutorial that I get from this project.

Tools requirement:

1. Basic PHP understanding
2. Basic SQL understanding
3. XAMPP installed and functional
4. Netbeans for PHP
5. GitHub account that can be accessed.
6. yEd (optional)
7. LibreOffice - Writer (optional)

After this project is finished, all files will be available here.