public/subjects/brackets.en.md

## brackets

### Instructions

Write a program that takes an undefined number of `string` in arguments. For each argument, if the expression is correctly bracketed, the program prints on the standard output `OK` followed by a newline (`'\n'`), otherwise it prints `Error` followed by a newline.

Symbols considered as brackets are parentheses `(` and `)`, square brackets `[` and `]` and curly braces `{` and `}`. Every other symbols are simply ignored.

An opening bracket must always be closed by the good closing bracket in the correct order. A `string` which does not contain any bracket is considered as a correctly bracketed `string`.

If there is no argument, the program must print only a newline.

### Usage

```console
student@ubuntu:~/piscine-go/brackets$ go build
student@ubuntu:~/piscine-go/brackets$ ./brackets '(johndoe)' | cat -e
OK$
student@ubuntu:~/piscine-go/brackets$ ./brackets '([)]' | cat -e
Error$
student@ubuntu:~/piscine-go/brackets$ ./brackets '' '{[(0 + 0)(1 + 1)](3*(-1)){()}}' | cat -e
OK$
OK$
student@ubuntu:~/piscine-go/brackets$ ./brackets | cat -e
$
student@ubuntu:~/piscine-go/brackets$
```