[leetcode] Reverse String 翻转字符串

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

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

这道题没什么难度，直接从两头往中间走，同时交换两边的字符即可，参见代码如下：

我的解法：

#include <iostream>
#include <vector>
#include <string>
#include <stdlib.h>
#include <stdio.h>
using namespace std;

class StringSolution {
public:
	string reverseString(string s) {

		string reversed(s);
		int index = 0;
		for (int i = s.length()-1; i >= 0; i--)
		{
			reversed[index++] = s[i];

		}
		return reversed;
	}
};


void main()
{


	string str = "wuzhigang";
	StringSolution ss;
	string results=ss.reverseString(str);

	cout << str.size() << endl;

	for (auto a : results)
	{
		cout << a ;
	}
	system("pause");
}

解法一：

class Solution {
public:
    string reverseString(string s) {
        int left = 0, right = s.size() - 1;
        while (left < right) {
            char t = s[left];
            s[left++] = s[right];
            s[right--] = t;
        }
        return s;
    }
};

我们也可以用swap函数来帮助我们翻转：

解法二：

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