Problem 42291. GJam 2015 Rd1B: Counter Culture
This Challenge is derived from GJam 2015 Rd 1B: Counter Culture. Fastest completion - 5 minutes.
Determine minimum sequence length to reach a number. Sequence starts at 1 and the next is either +1 or the number's reverse with trailing zeros removed. (eg 2300 is followed by 2301 or 32)
Input: N, a value from 1 to 1,000,000
Output: L, minimum length of sequence to reach N
Examples: Small Case 1<=N<=1000000
N=5, L=5 [1 2 3 4 5] L=N is true thru 19 N=23, L=15 [1:12 21 22 23]
Theory: The small case can be solved with brute force or semi-brute force using storage of past calculations. All values are processed at each depth level. Duplicates from [N+1 and flip] are purged. A fast reversal function is essential. Direct summation works well. The large case N limit is 1E14 making even semi-brute force with storage unlikely.
Additional GJam solutions can be found at Example GJam Matlab solutions. Select Find Solutions, change Language to Matlab. The Test Suite, at the bottom, contains a full GJam Matlab solution.
Solution Stats
Solution Comments
Show commentsProblem Recent Solvers10
Suggested Problems
-
4076 Solvers
-
304 Solvers
-
433 Solvers
-
618 Solvers
-
Replace all zeros and NaNs in a matrix with the string 'error'
99 Solvers
More from this Author308
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!