Question

Given an even length expression consisting only of { and }, find the min. Number of edits needed to make it a valid balanced expression.

Answer 1

Answer:

Input: exp = "}{"

Output: 2

We need to change '}' to '{' and '{' to

'}' so that the expression becomes balanced,

the balanced expression is '{}'

Input: exp = "{{{"

Output: Can't be made balanced using reversals

Input: exp = "{{{{"

Output: 2

Input: exp = "{{{{}}"

Output: 1

Input: exp = "}{{}}{{{"

Output: 3

Hope it helps you....