g0001_0100.s0012_integer_to_roman.Solution Maven / Gradle / Ivy
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Java Solution for LeetCode algorithm problems, continually updating
package g0001_0100.s0012_integer_to_roman;
// #Medium #String #Hash_Table #Math #2022_06_14_Time_7_ms_(75.71%)_Space_44.7_MB_(72.78%)
public class Solution {
public String intToRoman(int num) {
StringBuilder sb = new StringBuilder();
int m = 1000;
int c = 100;
int x = 10;
int i = 1;
num = numerals(sb, num, m, ' ', ' ', 'M');
num = numerals(sb, num, c, 'M', 'D', 'C');
num = numerals(sb, num, x, 'C', 'L', 'X');
numerals(sb, num, i, 'X', 'V', 'I');
return sb.toString();
}
private int numerals(StringBuilder sb, int num, int one, char cTen, char cFive, char cOne) {
int div = num / one;
switch (div) {
case 9:
sb.append(cOne);
sb.append(cTen);
break;
case 8:
sb.append(cFive);
sb.append(cOne);
sb.append(cOne);
sb.append(cOne);
break;
case 7:
sb.append(cFive);
sb.append(cOne);
sb.append(cOne);
break;
case 6:
sb.append(cFive);
sb.append(cOne);
break;
case 5:
sb.append(cFive);
break;
case 4:
sb.append(cOne);
sb.append(cFive);
break;
case 3:
sb.append(cOne);
sb.append(cOne);
sb.append(cOne);
break;
case 2:
sb.append(cOne);
sb.append(cOne);
break;
case 1:
sb.append(cOne);
break;
default:
break;
}
return num - (div * one);
}
}