Problem 44101. Adaptive ZigZag

Unfold a 2-D matrix to a 1-D array in Adaptive zig-zag order, e.g., for matrix

 [ 1 2 5 6;
   3 4 7 8;
   9 10 13 14;
   11 12 15 16]

the resulting 1-D array should be

 [ 1 5 9 13 2 3 4 6 7 8 10 11 12 14 15 16]

Solve

Last solution submitted on May 31, 2018

yurenchu on 25 Apr 2017

Sorry, the logic of what the problem suggests is not very clear to me. Should the input 2D matrix be broken up in 2-by-2 matrices first, and why?

J. S. Kowontan on 26 May 2018

@Bainhome, I believe your code cannot perform an adaptive zigzag scan of a valid 2x2 matrix due to the conditional statement implemented.

bainhome on 26 May 2018

S**t, a euqal sign is forgotten...THX buddy.

bainhome on 2 Aug 2018

What this code done to the index by using union is well-considered. Nice!