Wildcard Matching leetcode java

標籤：code   ring   不成功   問題   const   over   wildcard   ==   main   

描述
Implement wildcard paern 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

分析
跟上一題很類似。
主要是‘*‘ 的匹配問題。p 每遇到一個‘*‘，就保留住當前‘*‘ 的座標和 s 的座標，然後 s 從前
往後掃描，如果不成功，則 s++，重新掃描

代碼

 1 public class WildcardMatch { 2  3     public static void main(String[] args) { 4         // TODO Auto-generated method stu  5         String s= "aab"; 6         String p="*"; 7         System.out.println(isMatch(s,p)); 8     } 9 //    遞迴10         public static boolean isMatch(String s, String p) {11         if (p.length() == 0)12                 return s.length() == 0;13             14         if (p.charAt(0) == ‘*‘) {    15                 16         while (p!=null&&p.startsWith("*")) {17             18             p=p.substring(1); //跳過*19         }    20         if (p==null) 21             return true;22         while (s!= null && !isMatch(s, p)) 23             s=s.substring(1);24         return s != null;25       }26       27         else if (p.charAt(0) == ‘\0‘ || s.charAt(0) == ‘\0‘) return p.charAt(0) == s.charAt(0);28         else if (p.charAt(0) == s.charAt(0) || p.charAt(0) == ‘?‘) {29             30             return isMatch(s.substring(1), p.substring(1));31         }32         else return false;33         }



34 //迭代版    35     public static boolean isMatch2(String s, String p) {  36         int i = 0;  37         int j = 0;  38         int star = -1;  39         int mark = -1;  40         while (i < s.length()) {  41             if (j < p.length()  42                     && (p.charAt(j) == ‘?‘ || p.charAt(j) == s.charAt(i))) {  43                 ++i;  44                 ++j;  45             } else if (j < p.length() && p.charAt(j) == ‘*‘) {  46                 star = j++;  47                 mark = i;  48             } else if (star != -1) {  49                 j = star + 1;  50                 i = ++mark;  51             } else {  52                 return false;  53             }  54         }  55         while (j < p.length() && p.charAt(j) == ‘*‘) {  56             ++j;  57         }  58         return j == p.length();  59     }60 }

 

Wildcard Matching leetcode java