Rust Taskbook Level 10.6

Ask the user for a long word via the console. Display a list of words that can be formed from the letters of the entered word.

Given an arbitrary two-dimensional array:

[
	[11, 12, 13, 14, 15],
	[21, 22, 23, 24, 25],
	[31, 32, 33, 34, 35],
	[41, 42, 43, 44, 45],
	[51, 52, 53, 54, 55],
}

Zero out the elements below the main diagonal:

[
	[11, 12, 13, 14, 15],
	[ 0, 22, 23, 24, 25],
	[ 0,  0, 33, 34, 35],
	[ 0,  0,  0, 44, 45],
	[ 0,  0,  0,  0, 55],
}

Given some URL:

let url: &str = "http://test.com/dir1/dir2/dir3/page.html";

Given variables:

let num: u8 = 2;
let val: &str = "eee";

Replace the folder with the number num in the URL with the value val:

"http://test.com/dir1/eee/dir3/page.html"