Project Euler, Problem 24: Lexicographic Permutations

A permutation is an ordered arrangement of objects. For example, 3124 is one possible permutation of the digits 1, 2, 3 and 4. If all of the permutations are listed numerically or alphabetically, we call it lexicographic order. The lexicographic permutations of 0, 1 and 2 are:

012 021 102 120 201 210

What is the millionth lexicographic permutation of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9?

I used Narayana Pandita's algorithm to generate successive lexicographic permutations of my number set. I ran the algorithm 1,000,000 times to arrive at the answer. I made helper functions for each step of the algorithm.

Narayana Pandita's algorithm:

Find the largest index $k$ such that $a [k] < a [k + 1]$ . If no such index exists, the permutation is the last permutation.
Find the largest index $l$ greater than $k$ such that $a [k] < a [l]$ .
Swap the value of $a [k]$ with that of $a [l]$ .
Reverse the sequence from $a [k + 1]$ up to and including the final element $a [k]$ .

102,280