HT290WordPattern

思路

• 一个hashmap
• 一个hashmap
• 一个StringArray

易错

• 一旦用for开始循环，就要想到length==0的情况，尤其是string
• String should not use == to compare, should use _String.equals()

Some tricks

• String can be “” but is not null. Should use _String.length() to judge. Be smart to use _String.length() or _Array.length to get rid of corner cases.
• In HashMap, if you have to judge (containsValue), you may need to exchange the key and value to avoid this

Failed Test Cases

• Diff Keys but same values

"abba""dog dog dog dog"

• If too many chars in the pattern, the Index as Value Hash Map method would concur a problem that the length of pattern go beyond the length of Integer. We should use

Objects.equals(oneObject, theOtherObject)