标签：记录 update 倒序 .com string ret bing reference class
[Problem]
Given an input string, reverse the string word by word.
For example,
Given s = "the sky is blue",
return "blue is sky the".
Update (2015-02-12):
For C programmers: Try to solve it in-place in O(1) space.
[Idea]
从左往右遍历一次，每当遇到空格暂停，记录暂停位置作为开始点，移动二指针到下一个空格前的位置或者字符串末尾，则找到一个word。用一个新的空字符串result倒序存储每一个word。
双指针的方法。思想和实现都很简单。
[Code]
1 class Solution { 2 public: 3 void reverseWords(string &s) { 4 string result = ""; 5 for (int i = 0; i < s.length(); i++) { 6 if (s[i] != ‘ ‘) { 7 int pos = i; 8 while (i < s.length() && s[i] != ‘ ‘) i++; 9 if (result.length() > 0) result = ‘ ‘ + result; 10 result = s.substr(pos, i - pos) + result; 11 i--; 12 } 13 } 14 s = result; 15 } 16 };
update:
1 class Solution { 2 public: 3 void reverseWords(string &s) { 4 string result; 5 int i = 0; 6 while(i < s.size()) { 7 if(i < s.size() && s[i] == ‘ ‘) {i++; continue;} 8 string word; 9 while(i < s.size() && s[i] != ‘ ‘) { 10 word += s[i]; 11 i++; 12 } 13 if(result != "") result = ‘ ‘ + result; 14 result = word + result; 15 } 16 s = result; 17 } 18 };
[Reference]
Leetcode 151. Reverse Words in a String 解题报告
标签：记录 update 倒序 .com string ret bing reference class
原文地址：http://www.cnblogs.com/casperwin/p/6041306.html
