Create WildCardPatternMatching.cpp

Given a text and a wildcard pattern, implement wildcard pattern matching algorithm that finds if wildcard pattern is matched with text. The matching should cover the entire text (not partial text).

The wildcard pattern can include the characters ‘?’ and ‘*’
‘?’ – matches any single character
‘*’ – Matches any sequence of characters (including the empty sequence)

Author: sanjaymajhi

Algorithms/Dynamic Programming/C++/WildCardPatternMatching.cpp

@@ -0,0 +1,88 @@
+// C++ program to implement wildcard 
+// pattern matching algorithm 
+#include <bits/stdc++.h> 
+using namespace std; 
+
+// Function that matches input str with 
+// given wildcard pattern 
+bool strmatch(char str[], char pattern[], 
+			int n, int m) 
+{ 
+	// empty pattern can only match with 
+	// empty string 
+	if (m == 0) 
+		return (n == 0); 
+
+	// lookup table for storing results of 
+	// subproblems 
+	bool lookup[n + 1][m + 1]; 
+
+	// initailze lookup table to false 
+	memset(lookup, false, sizeof(lookup)); 
+
+	// empty pattern can match with empty string 
+	lookup[0][0] = true; 
+
+	// Only '*' can match with empty string 
+	for (int j = 1; j <= m; j++) 
+		if (pattern[j - 1] == '*') 
+			lookup[0][j] = lookup[0][j - 1]; 
+
+	// fill the table in bottom-up fashion 
+	for (int i = 1; i <= n; i++) 
+	{ 
+		for (int j = 1; j <= m; j++) 
+		{ 
+			// Two cases if we see a '*' 
+			// a) We ignore ‘*’ character and move 
+			// to next character in the pattern, 
+			//	 i.e., ‘*’ indicates an empty sequence. 
+			// b) '*' character matches with ith 
+			//	 character in input 
+			if (pattern[j - 1] == '*') 
+				lookup[i][j] = lookup[i][j - 1] || 
+							lookup[i - 1][j]; 
+
+			// Current characters are considered as 
+			// matching in two cases 
+			// (a) current character of pattern is '?' 
+			// (b) characters actually match 
+			else if (pattern[j - 1] == '?' || 
+					str[i - 1] == pattern[j - 1]) 
+				lookup[i][j] = lookup[i - 1][j - 1]; 
+
+			// If characters don't match 
+			else lookup[i][j] = false; 
+		} 
+	} 
+
+	return lookup[n][m]; 
+} 
+
+int main() 
+{ 
+	char str[] = "baaabab"; 
+	char pattern[] = "*****ba*****ab"; 
+	// char pattern[] = "ba*****ab"; 
+	// char pattern[] = "ba*ab"; 
+	// char pattern[] = "a*ab"; 
+	// char pattern[] = "a*****ab"; 
+	// char pattern[] = "*a*****ab"; 
+	// char pattern[] = "ba*ab****"; 
+	// char pattern[] = "****"; 
+	// char pattern[] = "*"; 
+	// char pattern[] = "aa?ab"; 
+	// char pattern[] = "b*b"; 
+	// char pattern[] = "a*a"; 
+	// char pattern[] = "baaabab"; 
+	// char pattern[] = "?baaabab"; 
+	// char pattern[] = "*baaaba*"; 
+
+	if (strmatch(str, pattern, strlen(str), 
+						strlen(pattern))) 
+		cout << "Yes" << endl; 
+	else
+		cout << "No" << endl; 
+
+	return 0; 
+}