Fixing naming convention

Hacker rank repository added.

Author: mirahman

Algorithms/Graph/Dijkstra.php

@@ -5,7 +5,7 @@
  * 
  */
 
-function Dijkstra(array $graph, string $source, string $target): array {
+function dijkstra(array $graph, string $source, string $target): array {
     $dist = [];
     $pred = [];
     $Queue = new SplPriorityQueue();
@@ -60,7 +60,7 @@ function Dijkstra(array $graph, string $source, string $target): array {
 $source = "A";
 $target = "F";
 
-$result = Dijkstra($graph, $source, $target);
+$result = dijkstra($graph, $source, $target);
 extract($result);
 
 echo "Distance from $source to $target is $distance \n";

Algorithms/Graph/Kruskal.php

@@ -7,7 +7,7 @@
  * 
  */
 
-function Kruskal(array $graph): array {
+function kruskal(array $graph): array {
     $len = count($graph);
     $tree = [];
 
@@ -67,7 +67,7 @@ function unionSet(array &$set, int $i, int $j) {
     [0, 0, 4, 2, 6, 0]
 ];
 
-$mst = Kruskal($graph);
+$mst = kruskal($graph);
 
 $minimumCost = 0;
 

Algorithms/Numbers-Maths/Sieve.php

@@ -0,0 +1,29 @@
+<?php
+
+/*
+ * Author: Mizanur rahman <[email protected]>
+ *
+ */
+
+function sieveOfEratosthenes(int $n)
+{
+
+    $prime = array_fill(0, $n + 1, true);
+
+    for ($p = 2; $p * $p <= $n; $p++) {
+        // If prime[p] is not changed, then it is a prime
+        if (isset($prime[$p]) && $prime[$p] == true) {
+            // Update all multiples of p
+            for ($i = $p * 2; $i <= $n; $i += $p)
+                $prime[$i] = false;
+        }
+    }
+
+    // Print all prime numbers
+    for ($p = 2; $p <= $n; $p++)
+        if ($prime[$p])
+            echo $p . " ";
+}
+
+
+sieveOfEratosthenes(5000000);

Algorithms/Recursion-DP-Others/BacktrackingSudoku.php

@@ -9,17 +9,17 @@
 define("N", 9);
 define("UNASSIGNED", 0);
 
-function SolveSudoku(array &$grid): bool {
+function solveSudoku(array &$grid): bool {
     $row = $col = 0;
 
-    if (!FindUnassignedLocation($grid, $row, $col))
+    if (!findUnassignedLocation($grid, $row, $col))
 	return true; // success! no empty space
 
     for ($num = 1; $num <= N; $num++) {
 	if (isSafe($grid, $row, $col, $num)) {
 	    $grid[$row][$col] = $num; // make tentative assignment
 
-	    if (SolveSudoku($grid))
+	    if (solveSudoku($grid))
 		return true;  // return, if success// return, if success
 
 	    $grid[$row][$col] = UNASSIGNED;  // failure, unmake & try again
@@ -28,23 +28,23 @@ function SolveSudoku(array &$grid): bool {
     return false; // triggers backtracking
 }
 
-function FindUnassignedLocation(array &$grid, int &$row, int &$col): bool {
+function findUnassignedLocation(array &$grid, int &$row, int &$col): bool {
     for ($row = 0; $row < N; $row++)
 	for ($col = 0; $col < N; $col++)
 	    if ($grid[$row][$col] == UNASSIGNED)
 		return true;
     return false;
 }
 
-function UsedInRow(array &$grid, int $row, int $num): bool {
+function usedInRow(array &$grid, int $row, int $num): bool {
     return in_array($num, $grid[$row]);
 }
 
-function UsedInColumn(array &$grid, int $col, int $num): bool {
+function usedInColumn(array &$grid, int $col, int $num): bool {
     return in_array($num, array_column($grid, $col));
 }
 
-function UsedInBox(array &$grid, int $boxStartRow, int $boxStartCol, int $num):bool {
+function usedInBox(array &$grid, int $boxStartRow, int $boxStartCol, int $num):bool {
     for ($row = 0; $row < 3; $row++)
 	for ($col = 0; $col < 3; $col++)
 	    if ($grid[$row + $boxStartRow][$col + $boxStartCol] == $num)
@@ -54,9 +54,9 @@ function UsedInBox(array &$grid, int $boxStartRow, int $boxStartCol, int $num):b
 
 function isSafe(array $grid, int $row, int $col, int $num): bool {
 
-    return !UsedInRow($grid, $row, $num) &&
-	    !UsedInColumn($grid, $col, $num) &&
-	    !UsedInBox($grid, $row - $row % 3, $col - $col % 3, $num);
+    return !usedInRow($grid, $row, $num) &&
+	    !usedInColumn($grid, $col, $num) &&
+	    !usedInBox($grid, $row - $row % 3, $col - $col % 3, $num);
 }
 
 /* A utility function to print grid  */
@@ -80,7 +80,7 @@ function printGrid(array $grid) {
     [0, 0, 2, 0, 9, 0, 5, 0, 0]
 ];
 
-if (SolveSudoku($grid) == true)
+if (solveSudoku($grid) == true)
     printGrid($grid);
 else
     echo "No solution exists";

Algorithms/Recursion-DP-Others/DNASequencing.php

@@ -11,7 +11,7 @@
 define("GP", -1);
 define("MS", -1);
 
-function NWSquencing(string $s1, string $s2) {
+function nwSquencing(string $s1, string $s2) {
     $grid = [];
     $M = strlen($s1);
     $N = strlen($s2);
@@ -89,4 +89,4 @@ function printSequence($grid, $s1, $s2, $j, $i) {
 
 $X = "GAATTCAGTTA";
 $Y = "GGATCGA";
-NWSquencing($X, $Y);
+nwSquencing($X, $Y);

Algorithms/Recursion-DP-Others/KMPMatching.php

@@ -5,14 +5,14 @@
  * 
  */
 
-function KMPStringMatching(string $str, string $pattern): array {
+function kmpStringMatching(string $str, string $pattern): array {
     $matches = [];
     $M = strlen($pattern);
     $N = strlen($str);
     $i = $j = 0;
     $lps = [];
 
-    ComputeLPS($pattern, $lps);
+    computeLPS($pattern, $lps);
 
     while ($i < $N) {
 	if ($pattern[$j] == $str[$i]) {
@@ -33,7 +33,7 @@ function KMPStringMatching(string $str, string $pattern): array {
     return $matches;
 }
 
-function ComputeLPS(string $pattern, array &$lps) {
+function computeLPS(string $pattern, array &$lps) {
     $len = 0;
     $i = 1;
     $M = strlen($pattern);
@@ -58,7 +58,7 @@ function ComputeLPS(string $pattern, array &$lps) {
 
 $txt = "AABAACAADAABABBBAABAA";
 $pattern = "AABA";
-$matches = KMPStringMatching($txt, $pattern);
+$matches = kmpStringMatching($txt, $pattern);
 
 if ($matches) {
     foreach ($matches as $pos) {

DS/Heap/Classes/MinHeap.php

@@ -7,77 +7,86 @@
 
 namespace DS\Heap\Classes;
 
-class MinHeap {
+class MinHeap
+{
 
     public $heap;
     public $count;
 
-    public function __construct(int $size) {
-	$this->heap = array_fill(0, $size + 1, 0);
-	$this->count = 0;
+    public function __construct(int $size)
+    {
+        $this->heap = array_fill(0, $size + 1, 0);
+        $this->count = 0;
     }
 
-    public function create(array $arr = []) {
-	if ($arr) {
-	    foreach ($arr as $val) {
-		$this->insert($val);
-	    }
-	}
+    public function create(array $arr = [])
+    {
+        if ($arr) {
+            foreach ($arr as $val) {
+                $this->insert($val);
+            }
+        }
     }
 
-    public function display() {
-	echo implode("\t", array_slice($this->heap, 1)) . "\n";
+    public function display()
+    {
+        echo implode("\t", array_slice($this->heap, 1)) . "\n";
     }
 
-    public function insert(int $i) {
-	if ($this->count == 0) {
-	    $this->heap[1] = $i;
-	    $this->count = 2;
-	} else {
-	    $this->heap[$this->count++] = $i;
-	    $this->siftUp();
-	}
+    public function insert(int $i)
+    {
+        if ($this->count == 0) {
+            $this->heap[1] = $i;
+            $this->count = 2;
+        } else {
+            $this->heap[$this->count++] = $i;
+            $this->siftUp();
+        }
     }
 
-    public function siftUp() {
-	$tmpPos = $this->count - 1;
-	$tmp = intval($tmpPos / 2);
+    public function siftUp()
+    {
+        $tmpPos = $this->count - 1;
+        $tmp = intval($tmpPos / 2);
 
-	while ($tmpPos > 0 && $this->heap[$tmp] > $this->heap[$tmpPos]) {
-	    $this->swap($tmpPos, $tmp);
-	    $tmpPos = intval($tmpPos / 2);
-	    $tmp = intval($tmpPos / 2);
-	}
+        while ($tmpPos > 0 && $this->heap[$tmp] > $this->heap[$tmpPos]) {
+            $this->swap($tmpPos, $tmp);
+            $tmpPos = intval($tmpPos / 2);
+            $tmp = intval($tmpPos / 2);
+        }
     }
 
-    public function swap(int $a, int $b) {
-	$tmp = $this->heap[$a];
-	$this->heap[$a] = $this->heap[$b];
-	$this->heap[$b] = $tmp;
+    public function swap(int $a, int $b)
+    {
+        $tmp = $this->heap[$a];
+        $this->heap[$a] = $this->heap[$b];
+        $this->heap[$b] = $tmp;
     }
 
-    public function extractMin() {
-	$min = $this->heap[1];
-	$this->heap[1] = $this->heap[$this->count - 1];
-	$this->heap[--$this->count] = 0;
-	$this->siftDown(1);
-	return $min;
+    public function extractMin()
+    {
+        $min = $this->heap[1];
+        $this->heap[1] = $this->heap[$this->count - 1];
+        $this->heap[--$this->count] = 0;
+        $this->siftDown(1);
+        return $min;
     }
 
-    public function siftDown(int $k) {
-	$smallest = $k;
-	$left = 2 * $k;
-	$right = 2 * $k + 1;
-	if ($left < $this->count && $this->heap[$smallest] > $this->heap[$left]) {
-	    $smallest = $left;
-	}
-	if ($right < $this->count && $this->heap[$smallest] > $this->heap[$right]) {
-	    $smallest = $right;
-	}
-	if ($smallest != $k) {
-	    $this->swap($k, $smallest);
-	    $this->siftDown($smallest);
-	}
+    public function siftDown(int $k)
+    {
+        $smallest = $k;
+        $left = 2 * $k;
+        $right = 2 * $k + 1;
+        if ($left < $this->count && $this->heap[$smallest] > $this->heap[$left]) {
+            $smallest = $left;
+        }
+        if ($right < $this->count && $this->heap[$smallest] > $this->heap[$right]) {
+            $smallest = $right;
+        }
+        if ($smallest != $k) {
+            $this->swap($k, $smallest);
+            $this->siftDown($smallest);
+        }
     }
 
 }

HackerRank/Euler/12.php

@@ -0,0 +1,63 @@
+<?php
+/**
+ * Author: Mizanur Rahman <[email protected]>
+ *
+ * Project Euler #12: Highly divisible triangular number
+ */
+
+$triangleNumbers = [];
+
+function numberOfDivisors($triangle) {
+
+    global $triangleNumbers;
+
+    if (isset($triangleNumbers[$triangle])) {
+        return $triangleNumbers[$triangle];
+    } else {
+        $tempTriangle = $triangle;
+        $primePowerCount = 1;
+        $count = 0;
+        while ($triangle % 2 == 0) {
+            $triangle =floor($triangle/ 2);
+            $count += 1;
+        }
+        $primePowerCount *= ($count + 1);
+        for ($i = 3; $i <= intval(sqrt($triangle)); $i++) {
+            $count = 0;
+            while ($triangle % $i == 0) {
+                $count += 1;
+                $triangle = floor($triangle/$i);
+            }
+            $primePowerCount *= ($count + 1);
+        }
+        if ($triangle > 2) {
+            $primePowerCount *= 2;
+        }
+        $triangleNumbers[$tempTriangle] = $primePowerCount;
+        return $triangleNumbers[$tempTriangle];
+    }
+}
+
+function getTriangle($number) {
+    return floor($number * ($number + 1)/ 2);
+}
+
+
+$handle = fopen ("php://stdin","r");
+$t = fgets($handle);
+for($i=0; $i<$t; $i++) {
+
+    $n = trim(fgets($handle));
+    $number = 1;
+    $triangle = getTriangle($number);
+    $divisorCount = numberOfDivisors($triangle);
+    $triangleNumbers[$number] = $divisorCount;
+    while ($divisorCount <= $n) {
+        $number += 1;
+        $triangle = getTriangle($number);
+        $divisorCount = numberOfDivisors($triangle);
+        $triangleNumbers[$triangle] = $divisorCount;
+
+    }
+    echo $triangle."\n";
+}