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Top 5 Common Programming Problems and How to Solve Them (With Code Examples)

Facing coding problems is a rite of passage for every developer, especially those just starting out. Whether you’re preparing for coding interview questions, strengthening your algorithmic thinking, or simply practicing to sharpen your skills, learning how to tackle common programming problems and solutions is a powerful way to grow. These challenges not only enhance your logical reasoning but also boost your confidence in handling real-world development tasks.
In this guide, weβll walk through five essential programming exercises, each paired with a specific programming language, complete solution code, and an in-depth explanation. These coding problems range from beginner to intermediate level and are frequently asked in interviews and technical assessments.
we’ll cover:
- πΉ 5 essential programming challenges
- πΉ Languages: Python, Java, JavaScript, C++
- πΉ Solutions with complete code blocks
- πΉ Detailed explanations and algorithm breakdown
This post is perfect for students, bootcamp learners, and job seekers looking to sharpen their skills.
π§ Problem 1: Reverse a String
- Language: Python
- Difficulty: Beginner
- Concepts: Slicing, Strings
β Solution Code:
def reverse_string(s):
return s[::-1]
print(reverse_string("CodingBrushup"))
π Code Explanation:
s[::-1]
uses Python’s slicing syntax.[::-1]
means start from the end and go backward, effectively reversing the string.- This method is concise and doesn’t require a loop, making it very Pythonic.
π’ Problem 2: Check if a Number is Prime
- Language: Java
- Difficulty: Easy to Intermediate
- Concepts: Loops, Math, Optimization
β Solution Code:
public class PrimeCheck {
public static boolean isPrime(int n) {
if (n <= 1) return false;
for (int i = 2; i <= Math.sqrt(n); i++) {
if (n % i == 0) return false;
}
return true;
}
public static void main(String[] args) {
System.out.println(isPrime(29));
}
}
π Code Explanation:
- A number is prime if divisible only by 1 and itself.
- Loop runs until βn because a larger factor would already have a smaller corresponding factor.
n % i == 0
checks for divisibility.
π Problem 3: Find the Factorial of a Number
- Language: JavaScript
- Difficulty: Intermediate
- Concepts: Recursion, Base Case, Call Stack
β Solution Code:
function factorial(n) {
if (n === 0) return 1;
return n * factorial(n - 1);
}
console.log(factorial(5));
π Code Explanation:
- This uses recursion to multiply the number
n
by the factorial of(n - 1)
. - The base case is
n === 0
, which returns 1 (since 0! = 1). - Useful for understanding recursion fundamentals.
π Problem 4: Find the Maximum Element in an Array
- Language: C++
- Difficulty: Beginner
- Concepts: Arrays, Loops, Conditionals
β Solution Code:
#include<iostream>
using namespace std;
int findMax(int arr[], int n) {
int max = arr[0];
for(int i = 1; i < n; i++) {
if(arr[i] > max)
max = arr[i];
}
return max;
}
int main() {
int arr[] = {3, 9, 2, 15, 6};
int n = sizeof(arr)/sizeof(arr[0]);
cout << "Max element: " << findMax(arr, n);
return 0;
}
π Code Explanation:
- Initialize
max
as the first element. - Loop through the rest and update
max
if a larger value is found. - Simple linear scan, O(n) time complexity.
π Problem 5: Check for Palindrome
- Language: Python
- Difficulty: Easy
- Concepts: String comparison, Slicing
β Solution Code:
def is_palindrome(s):
return s == s[::-1]
print(is_palindrome("madam"))
π Code Explanation:
- A palindrome reads the same forward and backward.
- Again using Python slicing to reverse the string and compare it with the original.
π Interactive Table: Summary of Problems
Problem | Language | Concept | Time Complexity |
---|---|---|---|
Reverse a String | Python | String, Slicing | O(n) |
Check Prime Number | Java | Loop, Math | O(βn) |
Find Factorial (Recursion) | JavaScript | Recursion | O(n) |
Find Max in Array | C++ | Loop, Arrays | O(n) |
Palindrome Check | Python | String | O(n) |
π Key Takeaways
- Practice with real coding problems enhances your logic-building skills.
- Understanding time complexity is crucial for efficient solutions.
- Pythonβs slicing, Java’s loops, JavaScript recursion, and C++ arrays all offer different but efficient problem-solving tools.
π£ Why Learn With CodingBrushup?
At CodingBrushup, we go beyond just teaching codeβwe empower developers to think algorithmically, practice real problems, and prepare for interviews. Our hands-on bootcamp covers problem-solving in Python, Java, JavaScript, and more, with expert guidance and real-world projects.
π Start your coding journey with CodingBrushup β where logic meets execution!