344. Reverse String

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

Example: Given s = “hello”, return “olleh”.

Code:

class Solution {
    public String reverseString(String s) {
        StringBuilder sb = new StringBuilder(s);
        return sb.reverse().toString();
    }
}

解题思路

• 使用使用字符串构造StringBuilder；
• 使用StringBuilder的reverse函数和toString函数。