[leetcode 44] Wildcard Matching

    

      Implement wildcard pattern matching with support for '?' and '*'.

    '?

' Matches any single character.
   '*' Matches any sequence of characters (including the empty sequence).
   The matching should cover the entire input string (not partial).
   The function prototype should be:
   bool isMatch(const char *s, const char *p)
   Some examples:
   isMatch("aa","a") → false
   isMatch("aa","aa") → true
   isMatch("aaa","aa") → false
  isMatch("aa", "*") → true
  isMatch("aa", "a*") → true
  isMatch("ab", "?*") → true
  isMatch("aab", "c*a*b") → false

  类似于正則表達式的匹配，当中两个字符串为空为true。当中'?

'不能够替换空串，'*'能够替换空串。

  AC代码：

class Solution
{
public:
    bool isMatch(string s, string p)
    {
        int len1=s.size();
        int len2=p.size();
        if(len1==0&&len2==0)
            return true;
        else if(len1==0)
        {
            int i=0;
            while(i<len2)
            {
                if(p[i]!='*')
                    return false;
                else
                    ++i;
            }
            return true;
        }
        else if(len2==0)
            return false;
        else
        {
            int i=0;
            int j=0;
            int pos_s=-1;
            int pos_p=-1;
            while(i<len1)
            {
                if(j<len2&&(s[i]==p[j]||p[j]=='?
'))
                {
                    ++i;
                    ++j;
                }
                else if(j<len2&&p[j]=='*')
                {
                    pos_s=i;
                    pos_p=j;
                    ++j;
                }
                else if(pos_p!=-1)
                {
                    i=++pos_s;
                    j=pos_p+1;
                    // ++pos_s;
                }
                else
                    return false;
            }
            while(j<len2&&(p[j]=='*'))
                ++j;
            if(j==len2)
                return true;
            else
                return false;
        }
    }
};

其它Leetcode题目AC代码：https://github.com/PoughER/leetcode