Number of Different Integers in a String

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class Solution:
    def numDifferentIntegers(self, word: str) -> int:
        for ch in word:
            # if the character is a letter, replace it with a space
            if ch.isalpha():
                word = word.replace(ch, ' ')

        # split the modified string into a list of numbers
        numbers = word.split()

        # create a set to store the unique numbers
        unique_numbers = set()

        for num in numbers:
            # remove leading zeros from each number and add it to the set
            stripped_num = num.lstrip('0')
            unique_numbers.add(stripped_num)

        # return the count of unique numbers
        return len(unique_numbers)

This code first replaces all letters in the string with spaces. Then it splits the modified string into a list of numbers. For each number in this list, it removes leading zeros and adds the resulting number to a set, which automatically removes duplicates. Finally, it returns the count of unique numbers in the set.

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class Solution:
    def numDifferentIntegers(self, word: str) -> int:
        s = {""}
        i = 0
        j = 0
        while j <= len(word):
            if j < len(word) and word[j].isdigit():
                if i < j and word[i] == '0':
                    i += 1
            else:
                s.add(word[i:j])
                i = j + 1
            j += 1
        return len(s) - 1

This code utilizes the concept of a sliding window. The window starts at index 0 and ends at the index where a non-digit character is found. The code ensures that leading zeros are skipped when adding a number to the set s. As a result, each distinct number (without leading zeros) is stored exactly once in s, which allows the function to return the count of distinct numbers by returning the size of the set s minus 1 (to exclude the empty string).