leetcode 83: Wildcard Matching

Wildcard MatchingMar 16 '12

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

 

 

uncompleted

public class Solution {
    public boolean isMatch(String s, String p) {
        // Start typing your Java solution below
        // DO NOT write main() function
        if(p.length() == 0) return s.length()==0 ? true : false;
        
        int i=0;
        char c;
        while(i<p.length() && i<s.length() && (c=p.charAt(i)) != '*') {
            if( c!='?' && c!=s.charAt(i) ) return false;
            i++;
        }
        
        int j=s.length()-1;
        int k=p.length()-1;
        
        while( j>=i && k>=i && (c=p.charAt(k)) != '*') {
            if( c!='?' && c!=s.charAt(j) ) return false;
            --j;
            --k;
        }
        
        if(i>j)return false;
        else s=s.substring(i,j+1);
        if(i>k) return false;
        else p=p.substring(i,k+1);
        
        String[] pattern = p.split("[*]");
        for(String temp:pattern){
            if(temp.length()>0){
                int index = getFirstIndex(s,temp);
                if(index<0) 
                    return false;
                else
                    s=s.substring(index+temp.length());
            }    
        }   
        return true;
    }
    
    public int getFirstIndex(String s, String p){
        if(s.length()<p.length()) return -1;
        int i=0;
        while(i<=s.length()-p.length()){
            while(i<s.length() && p.charAt(0)!='?' && p.charAt(0)!=s.charAt(i))
                i++;
            if(s.length()-i<p.length()) return -1;
            
            int j=i;
            while(j-i<p.length() && (p.charAt(j-i)=='?'||p.charAt(j-i)==s.charAt(j)))
                j++;
            if(j-i==p.length()) return i;
            i++;
        }
        return -1;
    }
}