Likou 58 - Left Rotation String

Title description

The left rotation operation of a string is to transfer several characters in front of the string to the end of the string.Please define a function to implement the function of the left rotation operation of the string.For example, if you enter the string "abcdefg" and the number 2, the function will return the result "cdefgab" obtained by left-rotating it two places.

Solution ideas

• This problem is very simple, just need to figure out StringBuffer's interception string operation function substring();
• Take two strings separately and change the order before and after to spell them together to complete the question.

Input and output example

Code

class Solution {public String reverseLeftWords(String s, int n) {int len ​​= s.length();StringBuffer sb = new StringBuffer();sb.append(s);String s1 = sb.substring(0,n);String s2 = sb.substring(n,len);String ss= s2+s1;return ss;}}