describe
There is a shift instruction in assembly language called Rotate Left (ROL). Now there is a simple task to simulate the operation result of this instruction with a string. For a given character sequence S, please rotate it to the left by K bits to output the sequence (guarantee that K is less than or equal to the length of S). For example, the character sequence S=”abcXYZdef” requires to output the result of 3-bit circular left shift, namely “XYZdefabc”. Is not it simple? OK, get it done!
example
Input: "abcXYZdef",3
Return value: "XYZdefabc"
answer
There is a method that is not the optimal solution, but it is relatively simple, string inversion
public class Solution {
public String LeftRotateString(String str,int n) {
if(n > str.length()){
return "";
}
String substring = str.substring(0, n);
String substring1 = str.substring(n);
return substring1+substring;
}
}