string反转问题

问题来源:

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问题描述:

Write a function that takes a string as input and returns the string reversed.

Example:
Given s = "hello", return "olleh".

我的解决方案(2种):

class Solution {
public:
     string reverseString(string s) {
         reverse(&s[0],&s[s.size()]);
         return s;
    }
};

class Solution {
public:
    string reverseString(string s) {
        string ret;
        for(int i=0;i<s.size();++i)
          ret.insert(0,1,s[i]);
        return ret;
    }
};

思考:

前几天做过部分反转string的题,所以这道题做的得心应手,reverse确实很方便,不过一定要记住是传的迭代器进去,另外摘录一个别的swap的做法,也很简单:

class Solution {
public:
    string reverseString(string s) {
        int i = 0, j = s.size() - 1;
        while(i < j){
            swap(s[i++], s[j--]); 
        }
        return s;
    }
};