Perform String Shifts - Leetcode

You are given a string s containing lowercase English letters, and a matrix shift, where shift[i] = [direction, amount]:

• direction can be 0 (for left shift) or 1 (for right shift). 
• amount is the amount by which string s is to be shifted.
• A left shift by 1 means remove the first character of s and append it to the end.
• Similarly, a right shift by 1 means remove the last character of s and add it to the beginning.

Return the final string after all operations.

Example 1:

Input: s = "abc", shift = [[0,1],[1,2]]
Output: "cab"
Explanation: 
[0,1] means shift to left by 1. "abc" -> "bca"
[1,2] means shift to right by 2. "bca" -> "cab"

Example 2:

Input: s = "abcdefg", shift = [[1,1],[1,1],[0,2],[1,3]]
Output: "efgabcd"
Explanation:  
[1,1] means shift to right by 1. "abcdefg" -> "gabcdef"
[1,1] means shift to right by 1. "gabcdef" -> "fgabcde"
[0,2] means shift to left by 2. "fgabcde" -> "abcdefg"
[1,3] means shift to right by 3. "abcdefg" -> "efgabcd"

Constraints:

• 1 <= s.length <= 100
• s only contains lower case English letters.
• 1 <= shift.length <= 100
• shift[i].length == 2
• 0 <= shift[i][0] <= 1
• 0 <= shift[i][1] <= 100

 class Solution {
    public String stringShift(String s, int[][] shift) {
      
        int i,j, amt = 0;
        int length = s.length();
        String sub1 = "", sub2 = "";
        for(i=0;i<shift.length;i++){
                if(shift[i][0] == 0){
                   amt = shift[i][1];
                    sub1 = s.substring(0,amt);
                    sub2 = s.substring(amt);
                    s = sub2+sub1;
                }
                else{
                    amt = shift[i][1];
                    sub1 = s.substring(length-amt);
                    sub2 = s.substring(0, length-amt);
                    s = sub1 + sub2;
                }
        }
      
        return s;
      
    }
}

Here, we are using substring concept in java.
i indicates length of array and j will be 0 and 1. So one for loop is enough.
If 0 do left shift by splitting string using substring and merge and store it in s.
If 1 do right shift by splitting string using substring and merge and store it in s.

Try it on Leetcode

If anyone had any different solution leave it as a comment.