本文实例讲述了php实现阿拉伯数字和罗马数字相互转换的方法。分享给大家供大家参考。具体如下:
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<?php // Function that calculates the roman string to the given number: function dec2roman( $f ) { // Return false if either $f is not a real number, //$f is bigger than 3999 or $f is lower or equal to 0: if (! is_numeric ( $f ) || $f > 3999 || $f <= 0) return false; // Define the roman figures: $roman = array ( 'M' => 1000, 'D' => 500, 'C' => 100, 'L' => 50, 'X' => 10, 'V' => 5, 'I' => 1 ); // Calculate the needed roman figures: foreach ( $roman as $k => $v ) if (( $amount [ $k ] = floor ( $f / $v )) > 0) $f -= $amount [ $k ] * $v ; // Build the string: $return = '' ; foreach ( $amount as $k => $v ) { $return .= $v <= 3 ? str_repeat ( $k , $v ) : $k . $old_k ; $old_k = $k ; } // Replace some spacial cases and return the string: return str_replace ( array ( 'VIV' , 'LXL' , 'DCD' ), array ( 'IX' , 'XC' , 'CM' ), $return ); } // echo dec2romen(1981); // Function to get the decimal value of a roman string: function roman2dec( $str = '' ) { // Return false if not at least one letter is in the string: if ( is_numeric ( $str )) return false; // Define the roman figures: $roman = array ( 'M' => 1000, 'D' => 500, 'C' => 100, 'L' => 50, 'X' => 10, 'V' => 5, 'I' => 1 ); // Convert the string to an array of roman values: for ( $i = 0; $i < strlen ( $str ); $i ++) if (isset( $roman [ strtoupper ( $str [ $i ])])) $values [] = $roman [ strtoupper ( $str [ $i ])]; // Calculate the sum of that array: $sum = 0; while ( $current = current( $values )) { $next = next( $values ); $next > $current ? $sum += $next - $current + 0 * next( $values ) : $sum += $current ; } // Return the value: return $sum ; } // echo roman2dec(IX); ?> |
希望本文所述对大家的php程序设计有所帮助。