Placement preparation

Days in a Given Month: Python, Java, C and C++ Programs

Python, Java, C, and C++ programs to find days in a given month and year. Covers the leap year rule, if-elif, array lookup, and standard library approaches.

Find the Quadrant of Given Coordinates: C Program and Explanation

Find the quadrant of any coordinate pair using a C program. Covers all four quadrants, origin, x-axis and y-axis cases, and O(1) complexity analysis.

Sum of All Numbers in a String: 4 Language Solutions

Step-by-step programs in Python, Java, C, and C++ to extract every number from a string and return their sum, with worked examples and complexity notes.

Sum of Array Elements: C, C++, Java, and Python

Find the sum of elements in a given array using loop-based programs and built-in functions in C, C++, Java, and Python, with examples and complexity analysis.

Sum of Perfect Square Elements in Array: C, C++, Java, Python

Find the sum of perfect square elements in an array in C, C++, Java, and Python. Algorithm, floating-point safety, traced example, and complexity analysis.

Sum of Boundary Elements of a Matrix: C, C++, Java, Python

Two complete approaches: O(N+M) optimised and O(N×M) check-each, to find the sum of boundary elements of a matrix, in C, C++, Java, and Python.

Program to Remove All Non-Alphabet Characters from a String

Step-by-step algorithm and verified C, C++, Java, and Python code to remove all non-alphabet characters from a string, with edge cases and O(n) complexity analysis.

Remove Duplicate Elements from an Array: Python, C++, Java

Remove array duplicates: two-pointer for sorted arrays (O(n), O(1) space); HashSet for unsorted (O(n), O(n) space). Code in Python, C++, and Java.

Find Nth Node from End of a Linked List: Two Approaches

Two methods to return the Nth node from the end of a linked list: the length-based two-pass approach and the single-pass two-pointer technique.

Reverse a Number in C, C++, Java and Python

Iterative and recursive approaches to reverse a number in C, C++, Java, and Python. Step-by-step trace, working code, and complexity analysis.

Reverse an Array: 4 Methods in C, Python, and Java

Four methods to reverse an array: print-from-end, auxiliary array, in-place swap, and recursion. Working code in C, Python, and Java with complexity analysis.

Swap Two Numbers Without a Third Variable

Three ways to swap two numbers without a third variable, with C code: arithmetic, XOR, and multiply-divide. Covers trade-offs, overflow risk, and what interviewers ask.

Pronoun-Antecedent Agreement: Sentence Correction Rules

Five pronoun-antecedent agreement error types tested in AMCAT, TCS NQT, and placement verbal sections. Rules, worked examples, and practice questions.

Function Prototype in C: Declaration, Syntax, and Why It Matters

A function prototype tells the C compiler the return type, argument count, and argument types before the function is defined. Learn what happens when you skip it.

Pyramid Pattern Programs Using Numbers: C, Python, Java

C, C++, Java, and Python code for seven number-pyramid variants, including Floyd's triangle and Pascal's triangle, with verified output for height 5.

9 May 2026 · 12 min read

Pyramid Star Patterns in C, C++, Java, and Python

Six pyramid star patterns with C, C++, Java, and Python code: right-angled, centered, inverted, hollow, and diamond. Loop logic and sample output for n=5.

9 May 2026 · 13 min read

Python Matrix Multiplication: Programs and Examples

Learn matrix multiplication in Python with nested loops and NumPy. Verified programs, step-by-step examples, and CRT placement test patterns for engineering students.

Python Nested Dictionaries with Example Programs

Create, access, modify, and iterate Python nested dictionaries with worked code examples. Covers .get() safety and patterns from placement coding rounds.

Types of Operators in Python: All 7 Types with Examples

Python has 7 operator types: arithmetic, comparison, logical, bitwise, assignment, identity, and membership. Learn each with code examples and placement tips.

Python print() Function: How to Print Output in Python

Complete guide to Python's print() function: syntax, sep, end, file, flush parameters, f-strings, and output formatting patterns for placement coding rounds.

Python: Remove a Character from a String (3 Methods)

Three Python methods to remove a character from a string: str.replace(), list comprehension with join(), and str.translate(). Code examples and edge cases included.

Python Program to Remove Duplicate Characters from a String

Three Python methods to remove duplicate characters from a string: simple loop, set-based O(n), and dict.fromkeys(). Covers verified outputs and time complexity.

Swap Two Variables in Python: All Four Methods

Four ways to swap two variables in Python: tuple unpacking, temp variable, arithmetic, and XOR, with code examples, derivations, and placement test context.

Python String Length: 5 Programs to Find Length of a String

Five methods to find string length in Python: len(), for loop, recursion, non-whitespace count, and Unicode code points vs grapheme clusters.

Rat in a Maze: Backtracking Algorithm with C++ Code

Solve the rat in a maze problem using backtracking in C++. Step-by-step algorithm, traced 4×4 example, and time and space complexity for placement interviews.

Reading Comprehension: Types of Questions in Aptitude Tests

Four question types appear in every placement RC passage: direct, inferential, vocabulary-in-context, and tone. Learn how to identify each and adjust your strategy.

Syllogism Part 2: Three-Premise Chains and Negative-Statement Traps

Builds on Venn basics with three-premise sorites chains, Celarent-Darii-Ferio named moods, Baroco, complementary pairs, and 10 verified worked examples.

Regular Expressions in Python: Complete Guide

Python's re module explained: metacharacters, special sequences, and pattern-matching methods. Includes worked examples for phone validation and email extraction.

Python Comparison Operators: All 6 With Examples

Python has six comparison operators that each return True or False. This guide covers ==, !=, >, <, >=, and <= with examples for numbers, strings, and chaining.

Remove All Non-Alphabet Characters from a String in Python

Three Python methods to strip digits, spaces, and symbols from a string, keeping only letters. Covers isalpha(), regex, and translate() with worked examples.

Remove Vowels from a String in Python: 4 Methods

Four Python methods to remove vowels from a string: for loop, list comprehension, filter(), and regex. With time complexity and placement coding round patterns.

Replace Array Elements with Their Rank: Two Approaches

Two approaches to replace each array element with its rank: O(n log n) HashMap and O(n²) brute force, with C++, Python, and Java code.

How to Return Multiple Values from a Function in C

C functions return one value by default. This guide covers four methods: pointers, structs, arrays, and malloc, with working code examples for placement test prep.

Selection Sort in C, C++, and Java with Code Examples

Selection sort code in C, C++, and Java with a step-by-step trace, O(N²) complexity analysis, stability notes, and a bubble sort comparison.

Python Sets Explained: Create, Modify, and Use Set Operations

Python sets store unique elements and check membership in O(1) time. Covers creation, set methods, operations, and placement coding patterns with examples.

Data Sufficiency: A Step-by-Step Method for Aptitude Tests

Data sufficiency tests your judgment, not your calculator. The step-by-step method that works for TCS NQT, AMCAT, and CAT placement rounds.

Sort Elements by Frequency in an Array: Three Approaches

Three approaches to sort array elements by frequency: brute force, hash map, and Python Counter, with complexity analysis and worked examples.

Spiral Order Matrix Printing: Step-by-Step Guide with Code

Print a 2D matrix in spiral order using four boundary pointers. Hand-traced 3x4 example, edge-case guards, and verified code in Python, C++, Java, and C.

Squaring Numbers 40 to 60: Aptitude Shortcuts for Placement Tests

Three mental math methods to square any number between 40 and 60 in under 5 seconds, with worked examples verified for campus placement aptitude tests.

Stick Game Problem: Solution and Code in Python, C, Java

Stick game on an n x m grid: derive why min(n, m) decides the winner, verify all three sample inputs, and get clean code in Python, C, and Java.

Subject-Verb Agreement: Sentence Correction Guide

Eight subject-verb agreement rules tested in AMCAT, TCS NQT, and placement verbal sections. Worked examples, common error traps, and practice questions.

Subset Sum Problem: Dynamic Programming, Code, and Complexity

Solve the subset sum problem using dynamic programming: step-by-step algorithm, tabulation walkthrough, Python and Java code, and time/space complexity.

Sum of Elements in Zigzag Sequence of a Matrix

Matrix zigzag traversal explained: scan each anti-diagonal in alternating directions, why the sum equals the total matrix sum, with code in Python, C++, and Java.

Syllogisms in Aptitude Tests: 3 Methods, 6 Rules, Solved Examples

Three methods and six rules cover every syllogism question in campus placement tests. Venn diagrams, verbal deduction, and tick-and-cross, with five worked examples.

10 Technical Interview and Aptitude Questions: Set 4

Ten solved questions on C pointer arithmetic, double pointers, scanf bugs, linked-list traversal, binary search, SQL filtering, first normal form, and FCFS scheduling.

10 C Programming Aptitude Questions with Answers

Ten C programming aptitude questions covering array out-of-bounds, pointer declarations, operator evaluation, and linkage types, with worked answers.

Python Ternary Operator: One-Line if-else with Examples

Write Python if-else logic in one line using the conditional expression. Syntax, five patterns, placement test output questions, and when to avoid nesting.

Partnership Problems: Types, Profit Sharing, and Solved Examples

Partnership aptitude problems: capital ratio, capital-time product, working partner salary. Five verified examples for TCS NQT, AMCAT, and campus placement tests.