fix: Correct mistakes in run-length-encode-and-huffman-encode.md (#298)

Author: Bert-Z

Diff for: assets/thinkings/huffman-example-fix.png

@@ -38,12 +38,12 @@ eg:
 
 结果是这样的：
 
-![huffman-example](../assets/thinkings/huffman-example.png)
+![huffman-example](../assets/thinkings/huffman-example-fix.png)
 
 |character|frequency|encoding|
 |:-:|:-:|:-:|
 |a|5|1100|
-|b|9|1110|
+|b|9|1101|
 |c|12|100|
 |d|13|101|
 |e|16|111|
@@ -85,4 +85,4 @@ AAAAABBBBCCC
 
 ## 相关题目
 
-[900.rle-iterator](../problems/900.rle-iterator.md)
+[900.rle-iterator](../problems/900.rle-iterator.md)