290. 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 non-empty word 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.

这道题和205神像，直接写方法了：

/**
 * @param {string} pattern
 * @param {string} str
 * @return {boolean}
 */
var wordPattern = function(pattern, str) {
    
    var word = "";
    var count = 0;
    var patternMap = {};
    var wordMap = {};
    str += " ";
    var num = str.length;
    for (var i = 0;i < num;i++) {
        if (str[i]!==" ") {
            word += str[i];
        } else {
            if (patternMap[pattern[count]]!==wordMap[word]) 
                return false;
            if (patternMap[pattern[count]]===undefined) {
                patternMap[pattern[count]] = count;
                wordMap[word] = count;
            }
            word = "";
            count++;
        }
    }
    if (count!==pattern.length)
        return false;
    return true;
};