## printcomb

### Instructions

Write a function that prints, in ascending order and on a single line: all **unique** combinations of three different digits so that, the first digit is lower than the second, and the second is lower than the third.

These combinations are separated by a comma and a space.

### Expected function

```go
func PrintComb() {

}
```

### Usage

Here is a possible program to test your function :

```go
package main

func main() {
	PrintComb()
}
```

This is the incomplete output :

```console
$ go run . | cat -e
012, 013, 014, 015, 016, 017, 018, 019, 023, ..., 689, 789$
$
```

- `000` or `999` are not valid combinations because the digits are not different.

- `987` should not be shown because the first digit is not less than the second.

### Notions

- [01-edu/z01](https://github.com/01-edu/z01)