标签：source length https eve href ice ble 数组 form
思路：字符串转化为char数组，从后遍历，如果是大写字母就转化为小写字母，如果是-就忽略，如果遍历了k个字符(排除-)就追加一个-。
Java实现1：insert版(StringBuilder的append()与insert()效率比较)
public String licenseKeyFormatting(String S, int K) {
StringBuilder sb = new StringBuilder();
char[] arr = S.toCharArray();
int count = 0;
for (int i = arr.length - 1; i >= 0; i--) {
char c = arr[i];
if (c == '-') continue;
if (count % K == 0) sb.insert(0, '-');
if (c >= 'a' && c <= 'z') c -= 32;
sb.insert(0, c);
count++;
}
// return sb.substring(0, sb.length() - 1); // "---" 不通过
return sb.length() > 0 ? sb.substring(0, sb.length() - 1) : "";
}
Java实现2：append版
public String licenseKeyFormatting(String S, int K) {
StringBuilder sb = new StringBuilder();
// char[] arr = S.toCharArray();
int count = 0;
for (int i = S.length() - 1; i >= 0; i--) {
char c = S.charAt(i);
if (c == '-') continue;
if (count % K == 0) sb.append('-');//sb.insert(0, '-');
if (c >= 'a' && c <= 'z') c -= 32;
sb.append(c);// sb.insert(0, c);
count++;
}
// return sb.substring(0, sb.length() - 1); // "---" 不通过
return sb.length() > 0 ? sb.reverse().substring(0, sb.length()-1) : "";
}
482. License Key Formatting - LeetCode
标签：source length https eve href ice ble 数组 form
原文地址：https://www.cnblogs.com/okokabcd/p/9206536.html
