wildcard matching

Change-Id: I08140e6cfda36be0e61abb8e169dc76984cd5216

Author: applewjg

WildcardMatching.java

@@ -0,0 +1,50 @@
+/*
+ Author:     King, [email protected]
+ Date:       Dec 20, 2014
+ Problem:    Wildcard Matching
+ Difficulty: Medium
+ Source:     https://oj.leetcode.com/problems/wildcard-matching/
+ Notes:
+ 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
+
+ Solution: 1. if s[i]  == p[j] || p[j] == '?', ++i and ++j.
+                ii, jj, record the positon of '*' in s and p, ++j and go on.
+                if not match, go back to star, i = ++ii;
+*/
+
+public class Solution {
+    public boolean isMatch(String s, String p) {
+        int ii = -1, jj = -1, i = 0, j = 0;
+        while (i < s.length()) {
+            if (j < p.length() && p.charAt(j) == '*') {
+                while (j < p.length() && p.charAt(j) == '*') ++j;
+                if (j == p.length()) return true;
+                ii = i;
+                jj = j;
+            }
+            if (j < p.length() && (p.charAt(j) == '?' || p.charAt(j) == s.charAt(i))) {
+                ++i; ++j;
+            } else {
+                if (ii == -1) return false;
+                ++ii;
+                i = ii;
+                j = jj;
+            }
+        }
+        while (j < p.length() && p.charAt(j) == '*') ++j;
+        return i == s.length() && j == p.length();
+    }
+}