Solution Exercise 57: python algorithm which determines the number of an occurrence within a given string

Exercise 57

Write a python algorithm as a function which takes a tuple of string (s, s1) as input and which returns the number of the occurrences of s1 within the string s without using any predefined method. Example: if s = "Python is object oriented and dynamically typed " and s1 = "ed" , the function returns 2.

Solution

To solve this problem, we can use a loop to iterate through each character of the string s and check if the current character and the next len(s1) - 1 characters match with the string s1. If they match, we increment a counter variable:

def count_occurrences(s, s1):
    count = 0
    for i in range(len(s) - len(s1) + 1):
        if s[i:i+len(s1)] == s1:
            count += 1
    return count
# Example:

s = "Python is object oriented and dynamically typed"
s1 = "ed"
count = count_occurrences(s, s1)
print(count)  # Output: 2

Younes Derfoufi
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