# LeetCode 541. Reverse String II

question:

Given a string and an integer k, you need to reverse the first k characters for every 2k characters counting from the start of the string. If there are less than k characters left, reverse all of them. If there are less than 2k but greater than or equal to k characters, then reverse the first k characters and left the other as original.

Example:

Input: s = "abcdefg", k = 2
Output: "bacdfeg"

Restrictions:

The string consists of lower English letters only.
Length of the given string and k will in the range [1, 10000]

try:

class Solution {    public String reverseStr(String s, int k) {        char[] charArray=s.toCharArray();        int length=charArray.length;        char[] result=new char[length];                for(int i=0;i<length;i++){            if((i/k)%2==0){                if(length<((i/k)*k+k)){                    result[length-1-i%k]=charArray[i];                    //continue;                }else{                    result[(i/k)*k+k-1-i%k]=charArray[i];                     }                            }else {                result[i]=charArray[i];            }                        }        return new String(result);    }}

result: 22.58%

conclusion:

posted @ 2018-05-01 12:21  Zhao_Gang  阅读(82)  评论(0编辑  收藏  举报