c++ 实现哈夫曼编译码器

#:0.2 E:0.105 T:0.071 O:0.0644 A:0.063 N:0.059 I:0.054 R:0.053 S:0.052 H:0.047 D:0.035 L:0.029 C:0.023 U:0.0225 F:0.0221 M:0.021 P:0.0175 Y:0.012 W:0.012 G:0.011 B:0.0105 V:0.008 K:0.003 X:0.002 J:0.001 Q:0.001 Z:0.001