leetcode(一)Word Pattern

题目描述：

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:

1. pattern = "abba", str = "dog cat cat dog" should return true.
2. pattern = "abba", str = "dog cat cat fish" should return false.
3. pattern = "aaaa", str = "dog cat cat dog" should return false.
4. pattern = "abba", str = "dog dog dog dog" should return false.

本人思路：把字符串转化为字符串数组后，先比较长度；再用pattern里的字符替换掉字符串。全部替换后再重新转化为字符串，并与pattern字符串相比较，得出结论。

代码如下（C#）：

public bool WordPattern(string pattern, string str) {
        //char[] patternAttr=new char[pattern.Length]
        char[] patternAttr=pattern.ToCharArray();
        string[] strAttr=str.Split(‘ ‘);
        if(patternAttr.Length!=strAttr.Length)
        {
            return false;
        }
        else
        {
            for(int i=0;i<strAttr.Length;i++)
            {
                for(int j=i;j<strAttr.Length;j++)
                {
                    if(strAttr[j]==strAttr[i])
                    {
                        strAttr[j]=patternAttr[i].ToString();
                    }
                    strAttr[i]=patternAttr[i].ToString();
                }
            }
            str=String.Join("",strAttr);
            if(str==pattern)return true;
            else return false;
        }
    }