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Алгоритмы → Конвертация числа в десятичное представление → PHP

Конвертация из заданной системы счисления в десятичную систему счисления

/* Show the steps for converting a number from a given base to base 10
Shows the steps involved in converting a number from a given base to base 10 */

<?php 
# Show the steps involved in converting a number 
# from any base (like octal or hex) to base 10

# See below for examples, instructions and copyright

function show_convert_to_base_10 ($number, $base) 
{ 
 // If the number contains a decimal component 
 if (strstr ($number, '.')) 
 { 
 // Get the integer and decimal components 
 list ($integer, $decimal) = explode ('.', $number); 
 } 
 else 
 { 
 // The number is an integer 
 $integer = $number; 
 } 
 
 print "Convert the base $base number $number to a 
 base 10 number:<blockquote>";

print "Convert the integer component ($integer) of the 
 number:<blockquote>";

// Compute the value of the integer component 
    // Loop through the integer digit by digit 
    // Reverse the number for easier handling 
    $integer = strrev ($integer); 
    $length  = strlen ($integer);

for ($pos = 0; $pos < $length; ++$pos) 
 { 
 /* 
 PHP lets you treat strings and numbers like arrays 
 Specify an offset and get the character at that 
 position 
 */ 
 
 $digit = $integer[$pos]; 
 
 // Handle character values for digits 
 // (for bases greater than 10) 
 if (eregi ('[a-z]', $digit)) 
 { 
 $digit_value = 
 (ord (strtolower ($digit)) 
 - ord ('a')) + 10; 
 
 $digit = "$digit ($digit_value)"; 
 } 
 else 
 { 
 $digit_value = $digit; 
 }

// Multiply the current digit by the radix 
 // raised to the power of the current position 
 $result = $digit_value * pow ($base, $pos); 
 
 print "Multiply the value of the digit at position 
 $pos by the value of the radix ($base) raised 
 to the power of the position ($pos): "; 
 
 print "$digit * $base$pos = $result 
 ";

$sums[] = $result; 
 } 
 print '</blockquote>';

if (isset ($decimal)) 
 { 
 print "Convert the decimal component (0.$decimal) 
 of the number:<blockquote>"; 
 
 // Pad the number with a leading 0 so that we can 
 // start at position 1 
 $decimal = '0'.$decimal; 
 $length = strlen ($decimal);

for ($pos = 1; $pos < $length; ++$pos) { 
 $digit = $decimal[$pos]; 
 
 // Handle character values for digits 
 // (for bases greater than 10) 
 if (eregi ('[a-z]', $digit)) 
 { 
 $digit_value = 
 (ord (strtolower ($digit)) 
 - ord ('a')) + 10;

$digit = "$digit ($digit_value)"; 
            } 
            else 
            { 
                 $digit_value = $digit; 
            } 
              
            // Multiply the current digit by the radix 
            // raised to the power of the current position 
            $result = $digit_value * pow (1/$base, $pos);

print "Multiply the value of the digit at 
 position $pos by the value of the 1/radix 
 ($base) raised to the power of the position 
 ($pos): "; 
 
 print "$digit * 1/$base$pos = 
 $result ";

$sums[] = $result; 
 } 
 print '</blockquote>'; 
 }

$sums = implode (' + ', $sums); 
    eval ("\$base_10_value = $sums;");

print "</blockquote>The value of the base $base number 
 $number in base 10 is $base_10_value. ";

print "This number is derived from the sum of the values 
 of the previous operations ($sums). "; 
}

/*   
DESCRIPTION   
 
show_convert_to_base_10: 
Shows the steps involved in converting a number from a given 
base to base 10. I wrote the example for a book, but after I 
was mostly finished it, it seemed too off topic.  I hope 
that someone finds it useful. :)

converting, number, php

tristlad

unknown

21.03.2008

Меню

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	Алгоритмы → Конвертация числа в десятичное представление → PHP Конвертация из заданной системы счисления в десятичную систему счисления /* Show the steps for converting a number from a given base to base 10 Shows the steps involved in converting a number from a given base to base 10 / <?php # Show the steps involved in converting a number # from any base (like octal or hex) to base 10 # See below for examples, instructions and copyright function show_convert_to_base_10 ($number, $base) { // If the number contains a decimal component if (strstr ($number, '.')) { // Get the integer and decimal components list ($integer, $decimal) = explode ('.', $number); } else { // The number is an integer $integer = $number; } print "<b>Convert the base $base number $number to a base 10 number:</b><blockquote>"; print "Convert the integer component ($integer) of the number:<blockquote>"; // Compute the value of the integer component // Loop through the integer digit by digit // Reverse the number for easier handling $integer = strrev ($integer); $length = strlen ($integer); for ($pos = 0; $pos < $length; ++$pos) { / PHP lets you treat strings and numbers like arrays Specify an offset and get the character at that position / $digit = $integer[$pos]; // Handle character values for digits // (for bases greater than 10) if (eregi ('[a-z]', $digit)) { $digit_value = (ord (strtolower ($digit)) - ord ('a')) + 10; $digit = "$digit ($digit_value)"; } else { $digit_value = $digit; } // Multiply the current digit by the radix // raised to the power of the current position $result = $digit_value pow ($base, $pos); print "Multiply the value of the digit at position $pos by the value of the radix ($base) raised to the power of the position ($pos):<br />"; print "$digit * $base<sup>$pos</sup> = $result <br /><br />"; $sums[] = $result; } print '</blockquote>'; if (isset ($decimal)) { print "Convert the decimal component (0.$decimal) of the number:<blockquote>"; // Pad the number with a leading 0 so that we can // start at position 1 $decimal = '0'.$decimal; $length = strlen ($decimal); for ($pos = 1; $pos < $length; ++$pos) { $digit = $decimal[$pos]; // Handle character values for digits // (for bases greater than 10) if (eregi ('[a-z]', $digit)) { $digit_value = (ord (strtolower ($digit)) - ord ('a')) + 10; $digit = "$digit ($digit_value)"; } else { $digit_value = $digit; } // Multiply the current digit by the radix // raised to the power of the current position $result = $digit_value * pow (1/$base, $pos); print "Multiply the value of the digit at position $pos by the value of the 1/radix ($base) raised to the power of the position ($pos):<br />"; print "$digit * 1/$base<sup>$pos</sup> = $result<br /><br />"; $sums[] = $result; } print '</blockquote>'; } $sums = implode (' + ', $sums); eval ("\$base_10_value = $sums;"); print "</blockquote>The value of the base $base number $number in base 10 is $base_10_value. <br />"; print "This number is derived from the sum of the values of the previous operations ($sums). <br /> <br />"; } /* DESCRIPTION show_convert_to_base_10: Shows the steps involved in converting a number from a given base to base 10. I wrote the example for a book, but after I was mostly finished it, it seemed too off topic. I hope that someone finds it useful. :) converting, number, php tristlad unknown 21.03.2008 Ваше имя Ваш E-mail (если хотите отслеживать комментарии) Дoкажи, что ты не робот Текст комментария	Меню CodeIgniter Алгоритмы Базы данных Дата и Время Интернет Интерфейс Мультимедиа ОС и Железо Работа с текстом Разное Технологии Файлы Подписка на RSS: Подпишись на RSS-ленту Поиск Облако тегов .net array asp bash browser charset check class clean convert count create css curl database date delete directory download element email equivalent extension file find form format function get height html http ie image javascript jquery load mysql number page perl php random scriplet send shell size sql string text time url utf8 variable vb visual basic width window xml xslt