Radix Sort

Radix sort: Sort digit by digit using stable counting sort.

$1.$ Find max to know digit count.

$2.$ For each digit position, counting sort on that digit.

Example $[170, 45, 75, 90, 802, 24, 2, 66]$:

• Ones: $[170, 90, 802, 2, 24, 45, 75, 66]$
• Tens: $[802, 2, 24, 45, 66, 170, 75, 90]$
• Hundreds: $[2, 24, 45, 66, 75, 90, 170, 802]$

Each pass stable, preserving earlier order when equal.