Leetcode 第290题Word Pattern

题目：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.

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题目分析：

• 字符串结构相似
• 方法：将两个字符串都转化为用数字表达的字符串，相同的字符用相同的数字来表示；最后判断两个字符串转换后的数字字符串是否相同

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代码：

• Javascript：

/**
 * @param {string} pattern
 * @param {string} str
 * @return {boolean}
 */
var wordPattern = function(pattern, str) {
    var arr_1=pattern.split("");
    var arr_2=str.split(" ");
    var str1=convert(arr_1);//将patter转换为数字字符串
    var str2=convert(arr_2);//将str转换为数字字符串
    if(str1==str2)//比较两个数字字符串相同时候返回true
    {
        return true;
    }
    else
    {
        return false;
    }
};
function convert(arr)//转换函数 将字符串转换为例如0110这样的字符串其中相同的数字代表相同的字符
{
    //var arr=str.split("");
    var tempArr=new Array();
    var a=0;

    var s1='';
    for(var i=0;i<arr.length;i++)
    {
        if(tempArr.indexOf(arr[i])==-1)//如果数组中不存在arr[i]那么将字符放入数字，将字符的下标与对应转换的数字对应起来
        {
            tempArr.push(arr[i]);
            s1+=''+a;
            a++;
        }
        else//如果数组中已经存在了arr[i]那么字符用其数组中的下标代替
        {
            s1+=''+tempArr.indexOf(arr[i]);
        }
    }
    return s1;
}