t)[e2][13 a45 清华大学們学院宋恒 清华大学软件学院宋 c1a]Q L] 清华大学学院未恒 清华大学软件学院宋 最小频率者最优编码可等长 Let c be an alphabet in which each character c C has frequency fIc]. Let x and y be tw characters in C having the lowest frequencie Then there exists an optimal prefix code for C in which the code words for x and y have the same length and differ only in the last bit 清华大学轼字院宋恒 消华大学软件学院宋3 清华大学软件学院宋斌恒 13 14 c:12 b:13 f:5 e:9 d:16 a:45 清华大学软件学院宋斌恒 14 14 d:16 a:45 f:5 e:9 25 c:12 b:13 清华大学软件学院宋斌恒 15 30 d:16 25 14 a:45 c:12 b:13 f:5 e:9 清华大学软件学院宋斌恒 16 55 30 d:16 25 14 a:45 c:12 b:13 f:5 e:9 清华大学软件学院宋斌恒 17 100 55 30 d:16 25 14 a:45 c:12 b:13 f:5 e:9 清华大学软件学院宋斌恒 18 最小频率者最优编码可等长 •Let C be an alphabet in which each character c ∈ C has frequency f [c].Let x and y be two characters in C having the lowest frequencies. • Then there exists an optimal prefix code for C in which the code words for x and y have the same length and differ only in the last bit