Ok, so first of all i don't know if it exist. But i will share my algorithm here only.

MOTIVATION!

Radix sort with base > 10?

so my motivation came when i though of why can't we use base 1e5 or 1e6 in radix sort? and i came up with following idea.

Most of the questions on CF have limit of values <=1e9. So my algorithm focuses majorily on that thing.

Alogirthm.

let us define a constant base, now we will make groups on the basis of ai % base,

• group[j] -> contains ai / base of those whoose ai % base == j.
• counts[j] -> it will store total number of times ai % base is equal to j. Note that both arrays will be of length base.

Next question — Now, how can we find the index of any value of any group?

Observe, let x be any value of group[i], then value = x * base + i, will be atleast bigger than prefix Sum of counts[i] upto x — 1, also value will be bigger than those value whoose group number is smaller.

Final touch

1. After making groups, and counts make prefix array of counts(let us call that array pref).
2. Define another array Live of length base, (initate all elements with 0).
3. Iterate from group 0 -> base. Now for every element(x) in this group(i) do the following
   • value = x * base + i
   • the index of this value = pref[x — 1] + live[x]
   • now do live[x] += 1
   • Update array[index] = value.

4. You have index of every value in the sorted array now, hence the sorting is done!