C Programming - MCQ Practice Questions

In competitive programming for graph problems, if adjacency list uses dynamic arrays, what is the time complexity of adding an edge?

What is the correct way to store variable-length strings dynamically?

What is the output of this code? #define ADD(a,b) a+b int result = ADD(5,3)*2;

What is the purpose of the #ifdef directive?

Which of the following shows the correct order of preprocessor directives in a C program?

What is the difference between #include <stdio.h> and #include "myheader.h"?

What will happen if you define the same macro twice with different values?

What is the output of this code? #define SWAP(a,b) {int temp=a; a=b; b=temp;} int x=5, y=10; SWAP(x,y); printf("%d %d", x, y);

What does the ## operator do in a macro?

What is the output? #define STR(x) #x printf("%s", STR(hello));

Consider the following code: #define MAX 100 #define MAX 200 What will be the result?

What will be the output of the following code? #define SQUARE(x) x*x int result = SQUARE(2+3); printf("%d", result);

What will be printed? #define DEBUG 1 #if DEBUG printf("Debug mode ON"); #else printf("Debug mode OFF"); #endif

What does the following macro do? #define CONCATENATE(a,b) a##b

What is the output of: #define STR(x) #x printf("%s", STR(HELLO));

What happens when you use #undef on a macro?

Which of the following will correctly find the maximum of two numbers using a macro?

Which of the following is the correct way to prevent multiple inclusion of a header file?

What is the output of the following code? #define SQUARE(x) x*x int a = SQUARE(5+3);

What will be the output of this preprocessor code? #define ADD(a,b) a+b int result = ADD(2,3)*2;