Regular Expression Matching

标签：dp

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

#include<iostream>
#include<vector>
#include<string>
using namespace std;

bool isMatch(const char *s, const char *p) {
	if (*p=='\0')
		return *s=='\0';
	if (*(p+1)=='*')
	{
		while (*s==*p||(*s != '\0' && *p == '.'))
		{
			if (isMatch(s, p+2))
				return true;
			else
				s++;
		}
		return isMatch(s, p+2);
	}
	else if(*s==*p||(*s != '\0' && *p == '.'))
		return isMatch(s+1, p+1);
	else
		return false;
}

Regular Expression Matching

标签：dp

原文地址：http://blog.csdn.net/li_chihang/article/details/44805923