Regular Expression Matching

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Implement regular expression matching with support for ‘.‘ and ‘*‘.

‘.‘ Matches any single character.
‘*‘ Matches zero or more of the preceding element.

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", "a*") → true
isMatch("aa", ".*") → true
isMatch("ab", ".*") → true
isMatch("aab", "c*a*b") → true

class Solution {
public:
    bool isMatch(const char *s, const char *p) {
        for( char c = *p; c != 0; ++s, c = *p ) {
            if( *(p+1) != ‘*‘ )
                p++;
            else if( isMatch( s, p+2 ) )
                return true;
            if( (*s==0) || ((c!=‘.‘) && (c!=*s)) )
                return false;
        }
        return *s == 0;
    }
};

Regular Expression Matching

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原文地址：http://www.cnblogs.com/code-swan/p/4141314.html