[LeetCode][JavaScript]Word Pattern

Word Pattern

Given a

pattern

and a string

str

, find if

str

follows the same pattern.

Here follow means a full match, such that there is a bijection between a letter in

pattern

and a substring in

str

.

Examples:

pattern =

"abba"

, str =

"dog cat cat dog"

should return true.

pattern =

"abba"

, str =

"dog cat cat fish"

should return false.

pattern =

"aaaa"

, str =

"dog cat cat dog"

should return false.

pattern =

"abba"

, str =

"dog dog dog dog"

should return false.

Notes:
You may assume

pattern

contains only lowercase letters, and

str

contains lowercase letters separated by a single space.

输入的str要匹配pattern的模式。

需要开两个哈希表，一个是pattern和str的映射，还有一个记录pattern有没有用过。

/**
* @param {string} pattern
* @param {string} str
* @return {boolean}
*/
var wordPattern = function(pattern, str) {
var dict = {}, used = {};
var strArr = str.split(' ');
if(pattern.length !== strArr.length){
return false;
}
for(var i = 0; i < strArr.length; i++){
if(!dict[strArr[i]]){
if(used[pattern[i]]){
return false;
}else{
used[pattern[i]] = true;
}
dict[strArr[i]] = pattern[i];
}else{
if(dict[strArr[i]] !== pattern[i]){
return false;
}
}
}
return true;
};