A C Programming Language Puzzle Last Updated : 21 Jun, 2018 Comments Improve Suggest changes Like Article Like Report Give a = 12 and b = 36 write a C function/macro that returns 3612 without using arithmetic, strings and predefined functions. We strongly recommend you to minimize your browser and try this yourself first. Below is one solution that uses String Token-Pasting Operator (##) of C macros. For example, the expression "a##b" prints concatenation of 'a' and 'b'. Below is a working C code. C #include <stdio.h> #define merge(a, b) b##a int main(void) { printf("%d ", merge(12, 36)); return 0; } Output: 3612 Thanks to an anonymous user to suggest this solution. Comment More infoAdvertise with us Next Article Company Wise Interview Preparation kartik Follow Improve Article Tags : C Language cpp-macros cpp-puzzle C-Macro & Preprocessor Similar Reads Interview Preparation Interview Preparation For Software Developers Must Coding Questions - Company-wise Must Do Coding Questions - Topic-wise Company-wise Practice Problems Company Preparation Competitive Programming Software Design-Patterns Company-wise Interview Experience Experienced - Interview Experiences Internship - Interview Experiences Practice @Geeksforgeeks Problem of the Day Topic-wise Practice Difficulty Level - School Difficulty Level - Basic Difficulty Level - Easy Difficulty Level - Medium Difficulty Level - Hard Leaderboard !! Explore More... Data Structures Arrays Linked List Stack Queue Binary Tree Binary Search Tree Heap Hashing Graph Advance Data Structures Matrix String All Data Structures Algorithms Analysis of Algorithms Searching Algorithms Sorting Algorithms Pattern Searching Geometric Algorithms Mathematical Algorithms Randomized Algorithms Greedy Algorithms Dynamic Programming Divide & Conquer Backtracking Branch & Bound All Algorithms Programming Languages C C++ Java Python C# Go Lang SQL PHP Scala Perl Kotlin Web Technologies HTML CSS JavaScript Bootstrap Tailwind CSS AngularJS ReactJS jQuery NodeJS PHP Web Design Web Browser File Formats Computer Science Subjects Operating Systems DBMS Computer Network Computer Organization & Architecture TOC Compiler Design Digital Elec. & Logic Design Software Engineering Engineering Mathematics Data Science & ML Complete Data Science Course Data Science Tutorial Machine Learning Tutorial Deep Learning Tutorial NLP Tutorial Machine Learning Projects Data Analysis Tutorial Tutorial Library Python Tutorial Django Tutorial Pandas Tutorial Kivy Tutorial Tkinter Tutorial OpenCV Tutorial Selenium Tutorial GATE CS GATE CS Notes Gate Corner Previous Year GATE Papers Last Minute Notes (LMNs) Important Topic For GATE CS GATE Course Previous Year Paper: CS exams Like