Last active
December 21, 2015 00:08
-
-
Save ile/6217307 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
# Linear partition | |
# Partitions a sequence of non-negative integers into k ranges | |
# Based on Óscar López implementation in Python (http://stackoverflow.com/a/7942946) | |
# Also see http://www8.cs.umu.se/kurser/TDBAfl/VT06/algorithms/BOOK/BOOK2/NODE45.HTM | |
# Dependencies: UnderscoreJS (http://www.underscorejs.org) | |
# Example: linear_partition([9,2,6,3,8,5,8,1,7,3,4], 3) => [[9,2,6,3],[8,5,8],[1,7,3,4]] | |
linear_partition = (seq, k) => | |
n = seq.length | |
return [] if k <= 0 | |
return seq.map((x) -> [x]) if k > n | |
table = (0 for x in [0...k] for y in [0...n]) | |
solution = (0 for x in [0...k-1] for y in [0...n-1]) | |
table[i][0] = seq[i] + (if i then table[i-1][0] else 0) for i in [0...n] | |
table[0][j] = seq[0] for j in [0...k] | |
for i in [1...n] | |
for j in [1...k] | |
m = _.min(([_.max([table[x][j-1], table[i][0]-table[x][0]]), x] for x in [0...i]), (o) -> o[0]) | |
table[i][j] = m[0] | |
solution[i-1][j-1] = m[1] | |
n = n-1 | |
k = k-2 | |
ans = [] | |
while k >= 0 | |
ans = [seq[i] for i in [(solution[n-1][k]+1)...n+1]].concat ans | |
n = solution[n-1][k] | |
k = k-1 | |
[seq[i] for i in [0...n+1]].concat ans |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment