HackerRank Python: Find a string Solution

Table of Contents

Question

In this challenge, the user enters a string and a substring. You have to print the number of times that the substring occurs in the given string. String traversal will take place from left to right, not from right to left.

NOTE: String letters are case-sensitive.

Input Format

The first line of input contains the original string. The next line contains the substring.

Constraints

$1 <= len(string) <= 200$

Each character in the string is an ascii character.

Output Format

Output the integer number indicating the total number of occurrences of the substring in the original string.

Sample Input

ABCDCDC
CDC

Sample Output

Concept

Some string processing examples, such as these, might be useful.
There are a couple of new concepts:
In Python, the length of a string is found by the function len(s), where s is the string.
To traverse through the length of a string, use a for loop:

for i in range(0, len(s)):
    print (s[i])

A range function is used to loop over some length:

range (0, 5)

Here, the range loops over 0 to 4. 5 is excluded.

Solution

				
					def count_substring(string, substring):
    count = 0
    sub_len = len(substring)
    for i in range(len(string) - sub_len + 1):
        if string[i:i+sub_len] == substring:
            count += 1
    return count

# Read the input string and substring
string = input().strip()
substring = input().strip()

# Call the count_substring function and print the result
result = count_substring(string, substring)
print(result)

Explanation

The function count_substring takes the string and substring as input and initializes the count variable to keep track of the number of occurrences.
It calculates the length of the substring using len(substring) and then iterates over the indices of the string using the range function. The loop variable i represents the starting index of a potential substring match.
Inside the loop, it checks if the substring starting at index i and ending at i+sub_len matches the given substring. If it matches, the count is incremented.
Finally, the function returns the total count of substring occurrences.
In the main code, the input string and substring are read from the user.
The count_substring function is called with the input string and substring, and the result is stored in the result variable.
The result is printed as the output.