05 August 2008
character array 都是一个个字符，其中可能有single space，根据space来前后单词reverse
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public void reverseWords(char[] s) {
// Three step to reverse
// 1, reverse the whole sentence
reverse(s, 0, s.length - 1);
// 2, reverse each word
int start = 0;
int end = -1;
for (int i = 0; i < s.length; i++) {
if (s[i] == ' ') {
reverse(s, start, i - 1);
start = i + 1;
}
}
// 3, reverse the last word, if there is only one word this will solve the corner case
reverse(s, start, s.length - 1);
}
public void reverse(char[] s, int start, int end) {
while (start < end) {
char temp = s[start];
s[start] = s[end];
s[end] = temp;
start++;
end--;
}
}