Counting Words With a Given Prefix
Problem :
Imagine you have a list of words, like [“apple”, “banana”, “apricot”, “grape”]. Now, suppose someone asks you, “How many of these words start with ‘ap’?” You’d say “apple” and “apricot”, right? That’s exactly what we need to do in this problem, but using a computer program.
In technical terms, “ap” is called a “prefix” – a little piece of a word that comes at the beginning. Our task is to write a program that counts how many words in a list start with a specific prefix.
Example to Understand Better
Let’s look at an example to understand this better:
- Our list of words (or “array of strings”) is [“pay”, “attention”, “practice”, “attend”].
- We want to find out how many of these words start with “at”.
If you look closely, “attention” and “attend” start with “at”. So, the answer is 2.
Solution :
class Solution:
def prefixCount(self, words, pref):
count = 0
for word in words:
if word.startswith(pref):
count += 1
return count
Why Is This Useful?
Learning to solve problems like this is super useful because it helps you think logically and methodically. It’s not just about counting words; it’s about breaking down a problem into smaller steps and solving it bit by bit. This skill is handy in many areas, not just in programming!
