Part $2$: Enhanced Delimiter Validation

Write a Java program that validates complex expressions with nested delimiters. In addition to checking parentheses $(),$ square brackets $[],$ and curly braces $\{\},$ this program will allow users to specify custom delimiter pairs $($e$.$g Your program should detect any delimiter errors, such as missing or unmatched delimiters, and specify the type of error and its location in the string.

To add complexity, you should:

$-$ Allow users to define custom delimiter pairs to be validated alongside the standard ones.

$-$ Attempt to suggest corrections for any errors you detect, such as indicating missing or misplaced delimiters. For example, if a $=\{($ b $+$ c $)*$ d $]$ is input, your program should suggest changing $]$ to $\}.$

$-$ Include a position$-$based analysis for unmatched delimiters, listing the exact position and type of each unmatched delimiter to help users correct their expression.

For this part, provide five test expressions in your report, including at least one with custom delimiters and one with incorrect nesting. Record and compare the time taken to validate expressions of varying complexity.

Draw a step$-$by$-$step diagram that shows the process your program follows to validate an expression and identify delimiter errors.