input: def editDistance(string1: str, string2: str) -> int:
      """
      Compute the edit distance between two strings.
      >>> editDistance("kitten", "sitting")
      3
      """
      m, n = len(string1), len(string2)
      dp = [[0 for x in range(n+1)] for x in range(m+1)]
      
      for i in range(m+1): 
          dp[i][0] = i 
    
      for j in range(n+1): 
          dp[0][j] = j 
    
      for i in range(1, m+1): 
          for j in range(1, n+1): 
              if string1[i-1] == string2[j-1]: 
                  dp[i][j] = dp[i-1][j-1] 
              else: 
                  dp[i][j] = 1 + min(dp[i][j-1], dp[i-1][j], dp[i-1][j-1])     
    
      return dp[m][n]
output:     
      m, n = len(string1), len(string2)
      dp = [[0 for x in range(n+1)] for x in range(m+1)]
      
      for i in range(m+1): 
          dp[i][0] = i 
    
      for j in range(n+1): 
          dp[0][j] = j 
    
      for i in range(1, m+1): 
          for j in range(1, n+1): 
              if string1[i-1] == string2[j-1]: 
                  dp[i][j] = dp[i-1][j-1] 
              else: 
                  dp[i][j] = 1 + min(dp[i][j-1], dp[i-1][j], dp[i-1][j-1])     
    
      return dp[m][n]
  