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Wildcard Pattern Matching

Certification: Advanced Level Accuracy: 0% Submissions: 0 Points: 15
p>Write a C++ program to implement a wildcard pattern matching algorithm. Given an input string `s` and a pattern `p`, implement a function that returns true if the pattern matches the string, and false otherwise. The pattern can include the wildcard character `*` (which matches any sequence of characters, including an empty sequence) and `?` (which matches any single character).
Example 1
    

  • Input: s = "aa", p = "a"
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  • Output: false
    • 

  • Explanation: 
      

    • Step 1: Initialize a dynamic programming approach to track matching states.
      • 

    • Step 2: Compare the pattern "a" against the string "aa".
      • 

    • Step 3: The pattern "a" only matches the first character of "aa".
      • 

    • Step 4: Since the pattern doesn't match the entire string, return false.
      • 

    •
Example 2
    

  • Input: s = "adceb", p = "*a*b"
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  • Output: true
    • 

  • Explanation: 
      

    • Step 1: Initialize a dynamic programming approach to track matching states.
      • 

    • Step 2: Process the pattern character by character:
   - First '*' can match empty string
   - 'a' matches 'a' in the string
   - Second '*' can match "dce"
   - 'b' matches 'b' in the string
      • 

    • Step 3: All pattern characters are matched.
      • 

    • Step 4: Return true as the pattern successfully matches the entire string.
      • 

    •
Constraints
    

  • 0 ≤ s.length, p.length ≤ 2000
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  • s contains only lowercase English letters
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  • p contains only lowercase English letters, '?' or '*'
    • 

  • Time Complexity: O(m*n) where m is the length of string and n is the length of pattern
    • 

  • Space Complexity: O(m*n)
    •
ArraysDynamic Programming KPMGeBay
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Hint
Solution

Solution Hints

    
  
  • Use dynamic programming to solve this problem efficiently
    • 
  
  • Create a 2D DP array to track matching status
    • 
  
  • Handle special cases like '*' matching empty sequences
    • 
  
  • Iterate through each character of the string and pattern
    • 
  
  • Consider using a greedy approach for optimization
    •

Steps to solve by this approach:

 Step 1: Create a 2D DP array where dp[i][j] represents if s[0...i-1] matches p[0...j-1].
 Step 2: Handle the base case: an empty pattern matches an empty string.
 Step 3: Pre-process patterns with '*' that can match empty sequences.
 Step 4: Iterate through each character of the string and pattern to fill the DP table.
 Step 5: For '*', consider both matching an empty sequence or matching the current character and extending.
 Step 6: For '?' or matching characters, carry forward the result from previous characters.
 Step 7: The final answer is stored in dp[m][n].

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