JAVAC - Java vs C ++

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Apologists of Java and C++ can argue for hours proving each other that their programming language is the best one. Java people will tell that their programs are clearer and less prone to errors, while C++ people will laugh at their inability to instantiate an array of generics or tell them that their programs are slow and have long source code.

Another issue that Java and C++ people could never agree on is identifier naming. In Java a multiword identifier is constructed in the following manner: the first word is written starting from the small letter, and the following ones are written starting from the capital letter, no separators are used. All other letters are small. Examples of a Java identifier are javaIdentifier, longAndMnemonicIdentifier, name, nEERC.

Unlike them, C++ people use only small letters in their identifiers. To separate words they use underscore character ‘_’. Examples of C++ identifiers are c_identifier, long_and_mnemonic_identifier, name (you see that when there is just one word Java and C++ people agree), n_e_e_r_c.

You are writing a translator that is intended to translate C++ programs to Java and vice versa. Of course, identifiers in the translated program must be formatted due to its language rules — otherwise people will never like your translator.

The first thing you would like to write is an identifier translation routine. Given an identifier, it would detect whether it is Java identifier or C++ identifier and translate it to another dialect. If it is neither, then your routine should report an error. Translation must preserve the order of words and must only change the case of letters and/or add/remove underscores.


The input file consists of several lines that contains an identifier. It consists of letters of the English alphabet and underscores. Its length does not exceed 100.


If the input identifier is Java identifier, output its C++ version. If it is C++ identifier, output its Java version. If it is none, output 'Error!' instead.




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makhan_28: 2021-04-19 11:16:08

thanks for the hints of edge cases in comments :)

Rafail Loizou: 2020-12-03 05:49:40

Numbers: You do not need to check about them he said what kind of input to expect and it doesn't include numbers.
First check if one of the 2 correct formats exists in the test case exactly with the conditions he said.
If it exists then go ahead and print the conversion otherwise report an error.
Also test cases don't have end of line at the end so just check if you reached the end of file. If no, read the next string and continue.

distructo: 2020-09-21 12:23:54

Damnn this question really have some cases

elucidase: 2020-06-26 08:47:08

Unclear instructions about boundary cases and whether there will be numbers.

kumar_anubhav: 2020-06-08 13:15:53

what if underscores are present at start and end ??

pradeep_7: 2020-05-17 13:51:43

WA :
1. adjacent '_'
2.last and first '_'
3.starting Capital

Suraj Prakash Sharma: 2019-08-31 00:09:46

@author The actual problem mentioned on the link specifies that the input file will only have one line containing identifier, If I go according to that, then I should write a solution which will be executed for every file containing one input. You are telling the input contains several lines containing identifier, atleast you should tell where the input will be terminated. At EOF or is there any special input where the input will be terminated. I am getting runtime error every-time I submit the code.

Last edit: 2019-08-31 00:21:10
prudhvi_495: 2019-06-16 14:06:20

First and last character should not be '_' and the first character should be small. underscores should not be adjacent.

Last edit: 2019-06-16 14:06:46
salman3007: 2018-10-18 04:29:15

After 10 wrong attempts!!

jyotiradityafc: 2018-08-26 13:35:47

use of isupper(), islower(), tolower(), toupper, basic, but shortens the code.
Corner cases:
- Starting letter should be small
- no underscore at last_
- no____multiple___underscores

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