Snake-like alignment in css - css

Question

I have been struggling with the following problem in CSS. I have an arbitrary number of items (spans or divs) that I want to wrap inside a container in a snake-like pattern.
What I mean by this is that if I have 10 items, which are each 20px wide, I would like them to display as follow in a 60px wide container:
0 1 2
5 4 3
6 7 8
9
I have tried using flexbox in CSS, but I can only get the items to display like this:
0 1 2
3 4 5
6 7 8
9
If that can help, I know the exact width of the individual items, but I do not know the width of the container.
Any help would be much appreciated.
Thank you in advance!

Answer 1

If you create your HTML structure with parent - rows - items you can use flex-direction: row-reverse on .row:nth-child(2n) elements and that will create desired result.
.content {
display: flex;
flex-direction: column;
}
.row {
display: flex;
justify-content: space-between;
}
.row:nth-child(2n) {
flex-direction: row-reverse;
}
.row:nth-child(2n):last-child .item {
margin-right: auto;
}
<div class="content">
<div class="row">
<div class="item">1</div>
<div class="item">2</div>
<div class="item">3</div>
</div>
<div class="row">
<div class="item">4</div>
<div class="item">5</div>
<div class="item">6</div>
</div>
<div class="row">
<div class="item">7</div>
<div class="item">8</div>
<div class="item">9</div>
</div>
<div class="row">
<div class="item">10</div>
</div>
</div>

Answer 2

Without knowing your markup limitations, you could use the following structure and float values to make it work.
.ltr, .rtl {
width: 60px;
}
.ltr div, .rtl div {
width: 20px;
height: 20px;
display: inline-block;
}
.rtl div {
float: right;
}
.ltr div {
float: left;
}
<div class="ltr">
<div>0</div><div>1</div><div>2</div>
</div>
<div class="rtl">
<div>3</div><div>4</div><div>5</div>
</div>
<div class="ltr">
<div>6</div><div>7</div><div>8</div>
</div>

Answer 3

Use the css direction: rtl;
demo here: http://codepen.io/sol_b/pen/YpjGKK
<div class="container">
<div class="row">
<span>1</span>
<span>2</span>
<span>3</span>
</div>
<div class="row2">
<span>4</span>
<span>5</span>
<span>6</span>
</div>
<div class="row">
<span>7</span>
<span>8</span>
<span>9</span>
</div>
</div>
.row2 {
direction: rtl;
float:left;
}
.row {
clear:both;
}