tags: String
#[LeetCode 186] Reverse Words in a String II Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters. The input string does not contain leading or trailing spaces and the words are always separated by a single space.
For example, Given s = "the sky is blue", return "blue is sky the".
Could you do it in-place without allocating extra space?
Diffculty
Medium
Similar Problems
这道题要求in-place做法，不能使用extra space, 那么，做法跟Rotate Array那道题非常相似 （1）reverse the whole array （2）reverse each subarray seperated by ' '
class Solution { public: void reverseWords(string s) { if (s.length == 0) return; std::reverse(s.begin(), s.end()); int last = 0; for (int i = 0; i < s.length; i++){ if (s[i] == ' ') { std::reverse(s.begin() + last, s.begin() + i-1); last = i + 1; } } }
// void reverse(string s, int l, int r) {
// while (l <= r) {
// int temp = s[l];
// s[l] = s[r];
// s[r] = temp;
// l++;
// r--;
// }
// }
};