PHP programs for printing pyramid patterns

This article is aimed at giving a PHP implementation for pattern printing.

Simple Pyramid Pattern

PHP

<?php
// Php code to demonstrate
// star pattern

// Function to demonstrate
// printing pattern
function pypart($n)
{

 // Outer loop to handle number
 // of rows in this case
 for ($i = 0; $i < $n; $i++)
 {

  // inner loop to handle
  // number of columns
  // values changing acc.
  // to outer loop
  for($j = 0; $j <= $i; $j++ )
  {

   // Printing stars
   echo "* ";
  }

  // ending line after
  // each row
  echo "\n";
 }
}

 // Driver Code
 $n = 5;
 pypart($n);
?>

Output :

* 
* * 
* * * 
* * * * 
* * * * * 

Time Complexity: The time complexity of this algorithm is O(N^2) where N is the number of rows.

Space Complexity: The space complexity of this algorithm is O(1) because only a fixed amount of memory is used.

After 180 degree rotation

PHP

<?php
// PHP code to demonstrate
// star pattern

// Function to demonstrate
// printing pattern
function pypart2($n)
{
 for ($i = 1; $i <= $n; $i++) {
  for ($j = 1; $j <= $n; $j++) {
   if($j<=($n-$i)){
    echo " "." ";

   }else {
    echo "* ";
   }

  }
  echo PHP_EOL;
 }
}

 // Driver Code
 $n = 5;
 pypart2($n);

?>

Output :

        * 
      * * 
    * * * 
  * * * * 
* * * * * 

Time Complexity: O(N^2) where N is the number of rows.

Space Complexity: O(1) because only a fixed amount of memory is used.

Printing Triangle

PHP

<?php
// PHP code to demonstrate
// star pattern

// Function to demonstrate
// printing pattern
function triangle($n)
{

 // number of spaces
 $k = 2 * $n - 2;

 // outer loop to handle
 // number of rows
 // n in this case
 for ($i = 0; $i < $n; $i++)
 {

  // inner loop to handle
  // number spaces
  // values changing acc.
  // to requirement
  for ($j = 0; $j < $k; $j++)
   echo " ";

  // decrementing k after
  // each loop
  $k = $k - 1;

  // inner loop to handle
  // number of columns
  // values changing acc.
  // to outer loop
  for ($j = 0; $j <= $i; $j++ )
  {

   // printing stars
   echo "* ";
  }

  // ending line after
  // each row
  echo "\n";
 }
}

 // Driver Code
 $n = 5;
 triangle($n);

?>

Output :

    * 
   * * 
  * * * 
 * * * * 
* * * * * 

Time complexity: O(N^2) where N is given number of rows
Auxiliary Space: O(1)

Star Triangle Pattern 2

PHP

<?php
 // code
// PHP code to demonstrate
// star pattern 2

// Function to demonstrate
// printing pattern 2
function triangle_pattern($len){
$string="*";
$pyramid_str="";
$mid_point=ceil($len/2);
for($i=1;$i<=$mid_point;$i++){
 for($j = 1; $j <= $i; ++$j) {
  $pyramid_str.=$string." ";
 }
 $pyramid_str.="\r\n";
}

for($i=$mid_point;$i>=1;$i--){
 for($j = 1; $j < $i; ++$j) {
  $pyramid_str.=$string." ";
 }
 $pyramid_str.="\r\n";
}

return $pyramid_str;
}
echo triangle_pattern(9);
?>

Output

* 
* * 
* * * 
* * * * 
* * * * * 
* * * * 
* * * 
* * 
* 

Time Complexity: O(n^2), where n is the input parameter. 

Space Complexity: O(n), where n is the input parameter.

Number Pattern

PHP

<?php
// PHP code to demonstrate
// printing pattern of numbers

// Function to demonstrate
// printing pattern
function numpat($n)
{

 // initializing starting number
 $num = 1;

 // outer loop to handle
 // number of rows
 // n in this case
 for ($i = 0; $i < $n; $i++)
 {

  // inner loop to handle
  // number of columns
  // values changing acc.
  // to outer loop
  for ($j = 0; $j <= $i; $j++ )
  {

   // printing number
   echo $num." ";
  }

   // incrementing number
   // at each column
   $num = $num + 1;

  // ending line after
  // each row
  echo "\n";
 }
}

 // Driver Code
 $n = 5;
 numpat($n);

?>

Output:

1 
2 2 
3 3 3 
4 4 4 4 
5 5 5 5 5 

Numbers without re assigning

PHP

<?php
// PHP code to demonstrate
// printing pattern of numbers

// Function to demonstrate
// printing pattern
function numpat($n)
{

 // initialising starting
 // number
 $num = 1;

 // outer loop to handle
 // number of rows
 // n in this case
 for ($i = 0; $i < $n; $i++)
 {

  // inner loop to handle
  // number of columns
  // values changing acc.
  // to outer loop
  for ($j = 0; $j <= $i; $j++ )
  {

   // printing number
   echo $num." ";

   // incrementing number
   // at each column
   $num = $num + 1;
  }

  // ending line after
  // each row
  echo "\n";
 }
}

 // Driver Code
 $n = 5;
 numpat($n);

?>

Output:

1 
2 3 
4 5 6 
7 8 9 10 
11 12 13 14 15 

Character Pattern

PHP

<?php
// PHP code to demonstrate printing
// pattern of alphabets

// Function to demonstrate
// printing pattern
function alphapat($n)
{

 // initializing value
 // corresponding to 'A'
 // ASCII value
 $num = 65;

 // outer loop to handle
 // number of rows
 // n in this case
 for ($i = 0; $i < $n; $i++)
 {

  // inner loop to handle
  // number of columns
  // values changing acc.
  // to outer loop
  for ($j = 0; $j <= $i; $j++ )
  {

   // explicitly converting
   // to char
   $ch = chr($num);

   // printing char value
   echo $ch." ";
  }

  // incrementing number
  $num = $num + 1;

  // ending line after
  // each row
  echo "\n";
 }
}

 // Driver Code
 $n = 5;
 alphapat($n);

?>

Output:

A 
B B 
C C C 
D D D D 
E E E E E 

Continuous Character pattern

PHP

<?php
// PHP code to demonstrate printing
// pattern of alphabets

// Function to demonstrate
// printing pattern
function contalpha($n)
{

 // initializing value
 // corresponding to 'A'
 // ASCII value
 $num = 65;

 // outer loop to handle
 // number of rows
 // n in this case
 for ($i = 0; $i < $n; $i++)
 {

  // inner loop to handle
  // number of columns
  // values changing acc.
  // to outer loop
  for ($j = 0; $j <= $i; $j++ )
  {

   // explicitly converting
   // to char
   $ch = chr($num);

   // printing char value
   echo $ch." ";

   // incrementing number
   // at each column
   $num = $num + 1;
  }

  // ending line after each row
  echo "\n";
 }
}

 // Driver Code
 $n = 5;
 contalpha($n);

?>

Output:

A 
B C 
D E F 
G H I J 
K L M N O 

Time complexity: O(n^2) where N is given input no of rows
Auxiliary Space: O(1)

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