Given a string of 1’s and 2’s, standing at index ‘i’, you can move exactly two steps forward or backward if s[i] == 2
, else you can move one step forward or backward if s[i] ==1
. A string is called a good string if you can reach the end of the string by moving every index exactly once.
Now, you have been given two Strings A and B (not necessarily good), you have to return the number of possible sub-sequences of swaps available, such that both the strings become good.
Swap means you can swap A[i]
with B[i]
.
Example:
A = 2211
B = 1111
ans = 8
Source : https://www.geeksforgeeks.org/media-net-interview-experience-for-sde-1/
Can someone please give some idea on how to solve this?