482. License Key Formatting
You are given a license key represented as a string S which consists only alphanumeric character and dashes. The string is separated into N+1 groups by N dashes.
Given a number K, we would want to reformat the strings 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 all lowercase letters should be converted to uppercase.
Given a non-empty string S and a number K, format the string according to the rules described above.
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.
Note:
package leetcode.easy;
public class LicenseKeyFormatting {
public String licenseKeyFormatting(String S, int K) {
StringBuffer sb = new StringBuffer();
int count = 0;
for (int i = S.length() - 1; i >= 0; i--) {
char c = S.charAt(i);
if (c != ‘-‘) {
if (count > 0 && count % K == 0) {
sb.append(‘-‘);
}
sb.append(c);
count++;
}
}
return sb.reverse().toString().toUpperCase();
}
@org.junit.Test
public void test() {
System.out.println(licenseKeyFormatting("5F3Z-2e-9-w", 4));
System.out.println(licenseKeyFormatting("2-5g-3-J", 2));
}
}
1
LeetCode_482. License Key Formatting
原文：https://www.cnblogs.com/denggelin/p/12034283.html