Rust Taskbook Level 4.10

Given a certain vector, for example, this one:

let vct = !vec[1, 2, 3, 4, 5, 6];

Divide the sum of the elements in even positions by the sum of the elements in odd positions.

Given a string:

"a bc def ghij"

Convert all substrings with less than or equal to three letters to uppercase. In our case, we should get the following:

"A BC DEF ghij"

There is a certain line with the words:

"aaa bbb ccc eee fff"

Capitalize the first character of every other word in that line. In our case, it should look like this:

"aaa Bbb ccc Eee fff"