Given a string which contains only letters. Sort it by lower case first and upper case second.
Note
It's not necessary to keep the original order of lower-case letters and upper case letters.
Example
For "abAcD", a reasonable answer is "acbAD"
Solution:
1 public class Solution { 2 /** 3 *@param chars: The letter array you should sort by Case 4 *@return: void 5 */ 6 public void sortLetters(char[] chars) { 7 int len = chars.length; 8 if (len <= 1) return; 9 10 int p1 = 0, p2 = len-1; 11 while (p1<len && chars[p1]>='a' && chars[p1]<='z') p1++; 12 while (p2>=0 && chars[p2]>='A' && chars[p2]<='Z') p2--; 13 while (p1<p2){ 14 //swap p1 and p2. 15 char temp = chars[p1]; 16 chars[p1] = chars[p2]; 17 chars[p2] = temp; 18 //find next swap positions. 19 while (p1<len && chars[p1]>='a' && chars[p1]<='z') p1++; 20 while (p2>=0 && chars[p2]>='A' && chars[p2]<='Z') p2--; 21 } 22 } 23 }