Form Minimum Number From a Given Sequence

Given a pattern containing only Is and Ds, I for increasing and D for decreasing, devise an algorithm to print the minimum number following that pattern. Digits are 1..9 and can’t repeat.


"D" should return 21.

"I" should return 12.

"DD" should return 321.

"II" should return 123.

"DIDI"should return 21435.

Contributed by Berkan Teber