LeetCode-in-Java
482. License Key Formatting
Easy
You are given a license key represented as a string s that consists of only alphanumeric characters and dashes. The string is separated into n + 1 groups by n dashes. You are also given an integer k.
We want to reformat the string s such that each group contains exactly k characters, except for the first group, which could be shorter than k but still must contain at least one character. Furthermore, there must be a dash inserted between two groups, and you should convert all lowercase letters to uppercase.
Return the reformatted license key.
Example 1:
Input: s = “5F3Z-2e-9-w”, k = 4
Output: “5F3Z-2E9W”
Explanation: The string s has been split into two parts, each part has 4 characters. Note that the two extra dashes are not needed and can be removed.
Example 2:
Input: s = “2-5g-3-J”, k = 2
Output: “2-5G-3J”
Explanation: The string s has been split into three parts, each part has 2 characters except the first part as it could be shorter as mentioned above.
Constraints:
1 <= s.length <= 105sconsists of English letters, digits, and dashes'-'.1 <= k <= 104
Solution
public class Solution {
public String licenseKeyFormatting(String s, int k) {
StringBuilder sb = new StringBuilder();
int cnt = 0;
int occ = 0;
for (char c : s.toCharArray()) {
if (c == '-') {
continue;
}
cnt++;
}
int l = cnt % k;
for (char c : s.toCharArray()) {
if (c == '-') {
continue;
}
if (occ == k) {
occ = 0;
sb.append('-');
} else if (occ == l && l != 0) {
l = 0;
occ = 0;
sb.append('-');
}
sb.append(Character.toUpperCase(c));
occ++;
}
return sb.toString();
}
}