s.s and push the index of each digit onto its corresponding stack.t and for each digit:
a. Check if the corresponding stack is empty. If it is, return false because the digit is not present in s.
b. Check if there are any smaller digits to the left of the current index that have not been moved. If there are, return false.
c. Pop the index from the stack to simulate moving the digit.t can be moved without any issues, return true.