10

Author: retaw

10_regular_expression_matching.cpp

@@ -0,0 +1,55 @@
+#include "test.h"
+
+class Solution
+{
+public:
+    bool isMatch(string s, string p)
+    {
+        return match(s, 0, p, 0);
+    }
+
+    bool match(const string& s, unsigned int i, const string& p, unsigned int j)
+    {
+        const char eof = 0;
+        char s1 = i < s.length() ? s[i] : eof;
+        char p1 = j < p.length() ? p[j] : eof;
+        char p2 = j + 1 < p.length() ? p[j + 1] : eof;
+
+        if (s1 == eof)
+        {
+            if (p1 == eof)
+                return true;
+			
+            if (p2 == '*')
+               return match(s, i, p, j + 2);
+           
+            return false;
+        }
+
+        if (p1 == s1 || p1 == '.')
+        {
+            return p2 == '*' ? (match(s, i + 1, p, j) || match(s, i, p, j + 2)): match(s, i + 1, p, j + 1);
+        }
+        else
+        {
+            return p2 == '*' ? match(s, i, p, j + 2) : false;
+        }
+
+        return true;
+    }
+};
+
+
+int main()
+{
+    Solution s;
+    cout
+    << s.isMatch("", "c*c*") << " "
+    << s.isMatch("aaa", "a*a") << " "
+    << s.isMatch("abc", "ab.*") << " "
+    << s.isMatch("abc", "ab.*") << " "
+    << s.isMatch("abccccc", "abc.*") << " "
+    << s.isMatch("abccccc", "abc.*d") << " "
+    << endl;
+
+}

Makefile

@@ -8,6 +8,7 @@ targets = \
 	7_reverse_interger.exec\
 	8_string_to_interger.exec\
 	9_palindrome_number.exec\
+	10_regular_expression_matching.exec\
 
 
 CC = g++