[leetcode 334]Reverse String.md

Question:

Write a function that takes a string as input and returns the string reversed.
Example:
Given s = "hello", return "olleh".

Code:

Here is Java:

public class Solution {
    public String reverseString(String s) {
        StringBuffer buffer = new StringBuffer();
        if(s==null || s.isEmpty()) return s ;
        for(int i=s.length()-1; i>=0; i--){
            buffer.append(s.charAt(i));
        }
        return buffer.toString();
    }
}

// 两边一起走自然是更快的
public class Solution {
    public String reverseString(String s) {
        if(s==null || s.isEmpty()) return s ;

        int left = 0 ;
        int right = s.length()-1;
        char[] array = s.toCharArray() ;
        while(left<right){
            char temp = array[left] ;
            array[left++] = array[right];
            array[right--] = temp ;
        }

        return String.valueOf(array);
    }
}

// stringBuffer and StringBuild maybe a better answer
public class Solution {
    public String reverseString(String s) {
       StringBuffer() sb = new StringBuffer(s);
       return s.reverse().toString();
    }
}

And JS

/**
 * @param {string} s
 * @return {string}
 */
var reverseString = function(s) {
    
    return s.split("").reverse().join("") ;
};

python 大法好

class Solution(object):
    def reverseString(self, s):
        """
        :type s: str
        :rtype: str
        """
        return s[::-1]