Changes in Edit Function
- minor changes to the logic problem
- change magic numbers to enum constants
- test cases for null inputs
- test cases for new enum constants
Revert "Changes in Edit Function"

This reverts commit 1a13fce58ab518af11369f81484b77d94a0b116f.
Changes in Edit Function
- minor changes to the logic problem
- change magic numbers to enum constants
- test cases for null inputs
- test cases for new enum constants