public class Solution {
public String reverseWords(String s) {
int len = s.length();
if (len == 1) {
return s;
}
char[] charArr = s.toCharArray();
int begin = 0;
for (int i = 0; i < len; i++) {
if (s.charAt(i) == ' ') {
reverseCharArray(charArr, begin, i - 1);
begin = i + 1;
}
}
reverseCharArray(charArr, begin, len - 1);
return String.valueOf(charArr);
}
private void reverseCharArray(char[] arr, int index1, int index2) {
while (index1 < index2) {
swap(arr, index1, index2);
index1++;
index2--;
}
}
private void swap(char[] arr, int l, int r) {
char temp = arr[l];
arr[l] = arr[r];
arr[r] = temp;
}
}
