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

Solution:

func stringShift(s string, shift [][]int) string {
    sumRight := 0
    for _,v := range shift {
        switch v[0]{
            case 0:
                sumRight = sumRight - v[1]
            case 1:
                sumRight = sumRight + v[1]
        }
    }
    rs := []rune(s)
    result := []rune{}
    sumRight = sumRight % len(s)
    shiftPoint := 0
    switch {
        sumRight > 0:
            shiftPoint = lenS - sumRight
        default:
            shiftPoint = -sumRight
    }
    result = append(result, rs[shiftPoint: ]... )
    result = append(result, rs[0: shiftPoint]...)
    
    return  string(result)
}