[原题链接-M] (https://leetcode.com/problems/integer-to-roman/description/)
Example
罗马数字问题
时间复杂度: O(N)- 空间复杂度: O(1)
这个题关键点在于穷举
print_r(test(1994));
function test($num) {
$lookup = [
'M' => 1000,
'CM'=> 900,
'D'=> 500,
'CD'=> 400,
'C'=> 100,
'XC'=> 90,
'L'=> 50,
'XL'=> 40,
'X'=> 10,
'IX'=> 9,
'V'=> 5,
'IV'=> 4,
'I'=> 1
];
$roman = '';
foreach ($lookup as $key => $value) {
while ($num >= $value) {
$roman .= $key;
$num -= $value;
}
}
return $roman;
}
