【leetcode_easy】557. Reverse Words in a String III

problem

557. Reverse Words in a String III

solution1:字符流处理类istringstream.

class Solution {
public:
    string reverseWords(string s) {
        string ans = "", t = "";
        istringstream is(s);//
        while(is >> t)
        {
            reverse(t.begin(), t.end());
            ans += t + " ";//err.
        }
        ans.pop_back();
        return ans;        
    }
};

solution2:单词首尾指针。

 

class Solution {
public:
    string reverseWords(string s) {
        int start = 0, end = 0;
        while(start<s.size() && end<s.size())
        {
            while(end < s.size() && s[end]!=' ') end++;
            for(int i=start, j=end-1; i<j; i++, j--)//
            {
                swap(s[i], s[j]);//
            }
            start = ++end;
            //start = end + 1;
            //end++;
        }
        return s;
    }
};

 

 

参考

1. Leetcode_easy_557. Reverse Words in a String III;

2. Grandyang;

完