Editing Huffman coding (section)

=== {{anchor|Length-limited Huffman coding|Minimum variance Huffman coding}}Length-limited Huffman coding/minimum variance Huffman coding ===
'''Length-limited Huffman coding''' is a variant where the goal is still to achieve a minimum weighted path length, but there is an additional restriction that the length of each codeword must be less than a given constant. The [[package-merge algorithm]] solves this problem with a simple [[Greedy algorithm|greedy]] approach very similar to that used by Huffman's algorithm. Its time complexity is <math>O(nL)</math>, where <math>L</math> is the maximum length of a codeword. No algorithm is known to solve this problem in [[Big O notation#Orders of common functions|<math>O(n)</math> or <math>O(n\log n)</math>]] time, unlike the presorted and unsorted conventional Huffman problems, respectively.