Pattern Finder

Part of the Fundamentals section of Coddy's R journey — lesson 77 of 78.

Challenge

Easy

Create a function called count_pattern that takes two arguments: text and pattern. The function should return the number of times the pattern appears in the text, including overlapping occurrences.

You will receive two lines of input:

The text string to search in
The pattern string to search for

Call your function with the provided inputs and print the result.

Hints:

Use nchar() to get the length of strings
Use substr(text, start, stop) to extract substrings
Iterate through each valid starting position and check if the substring matches the pattern

For example, if the input is:

ababa
aba

The output should be:

Explanation: The pattern "aba" appears at position 1 (ababa) and position 3 (ababa), so the count is 2.

If the input is:

mississippi
issi

The output should be:

Try it yourself

# Read input
con <- file("stdin", "r")
text <- suppressWarnings(readLines(con, n = 1))
pattern <- suppressWarnings(readLines(con, n = 1))
close(con)

# TODO: Create a function called count_pattern that takes text and pattern
# and returns the count of overlapping occurrences of pattern in text


# Call the function and print the result
print(count_pattern(text, pattern))