15 Most Repeated Coding Questions in Infosys, TCS & Wipro Interviews

✅ The 15 Most Repeated Questions (With Easy-to-Understand Code Snippets)

Each code snippet below is simplified and beginner-friendly. Suitable for students from any background.

1. Two Sum Problem

Problem: Given an array and a target, find two numbers that add up to the target.

Python:

def two_sum(nums, target):
    for i in range(len(nums)):
        for j in range(i + 1, len(nums)):
            if nums[i] + nums[j] == target:
                return [i, j]

2. Check Palindrome

Problem: Check if a string is the same forward and backward.

Python:

def is_palindrome(s):
    return s == s[::-1]

3. Anagram Check

Problem: Check if two strings have the same letters.

Python:

def is_anagram(s1, s2):
    return sorted(s1) == sorted(s2)

4. Remove Duplicates from Array

Python:

def remove_duplicates(arr):
    unique = []
    for num in arr:
        if num not in unique:
            unique.append(num)
    return unique

5. Fibonacci Series

Python:

def fibonacci(n):
    a, b = 0, 1
    for _ in range(n):
        print(a, end=' ')
        a, b = b, a + b

6. Reverse a String

Python:

def reverse_string(s):
    return s[::-1]

7. Factorial (Recursion)

Python:

def factorial(n):
    if n == 0 or n == 1:
        return 1
    else:
        return n * factorial(n - 1)

8. Missing Number in Array

Python:

def find_missing(arr, n):
    expected_sum = n * (n + 1) // 2
    actual_sum = sum(arr)
    return expected_sum - actual_sum

9. Maximum Occurring Character

Python:

def max_char(s):
    freq = {}
    for char in s:
        freq[char] = freq.get(char, 0) + 1
    return max(freq, key=freq.get)

10. Count Vowels and Consonants

Python:

def count_vowels_consonants(s):
    vowels = 'aeiouAEIOU'
    v = 0
    c = 0
    for i in s:
        if i.isalpha():
            if i in vowels:
                v += 1
            else:
                c += 1
    return v, c

11. Sort Array of 0s, 1s, 2s

Python:

def sort_zeros_ones_twos(arr):
    return sorted(arr)

12. Second Largest Element

Python:

def second_largest(arr):
    arr = list(set(arr))  # remove duplicates
    arr.sort()
    return arr[-2] if len(arr) >= 2 else None

13. Find Duplicates in Array

Python:

def find_duplicates(arr):
    seen = set()
    duplicates = []
    for num in arr:
        if num in seen:
            if num not in duplicates:
                duplicates.append(num)
        else:
            seen.add(num)
    return duplicates

14. Check Prime Number

Python:

def is_prime(n):
    if n <= 1:
        return False
    for i in range(2, int(n**0.5) + 1):
        if n % i == 0:
            return False
    return True

15. Balanced Parentheses

Python: