NCCS C 1st Sem Pre Board Solution

1. Difference between actual and formal parameters

Actual parameters: Values/variables passed to a function when it is called
Formal parameters: Variables declared in the function definition to receive the passed values

Example:

void sum(int a, int b); // a and b are formal parameters
sum(x, y);              // x and y are actual parameters

1 2	void sum(int a, int b); // a and b are formal parameters sum(x, y); // x and y are actual parameters

2. Use of ftell() and rewind() functions

ftell(): Returns the current file position indicator (in bytes) of the file stream
Example: long pos = ftell(filePtr);
rewind(): Sets the file position indicator to the beginning of the file
Example: rewind(filePtr);

3. Four keywords of C

int
if
return
while
(Other examples: char, float, for, switch)

4. NULL pointer

A pointer that doesn’t point to any memory location (value 0). Used to indicate that the pointer is not currently valid or initialized.

Example:

int *ptr = NULL;

1	int *ptr = NULL;

5. When to use -> (arrow) operator

Used to access members of a structure or union through a pointer to that structure/union.

Example:

struct Student { char name[20]; };
struct Student *sptr;
sptr->name; // Equivalent to (*sptr).name

struct Student { char name[20]; };

struct Student *sptr;

sptr->name; // Equivalent to (*sptr).name

6. What’s wrong with: `name = "NCCS"`

name must be a character array or pointer
For arrays, use strcpy(name, "NCCS")
For pointers, first allocate memory

Correct versions:

char name[20]; strcpy(name, "NCCS"); // Array version
char *name = malloc(20); strcpy(name, "NCCS"); // Pointer version

1 2	char name[20]; strcpy(name, "NCCS"); // Array version char *name = malloc(20); strcpy(name, "NCCS"); // Pointer version

7. Can { } be used for single line of code?

Yes, curly brackets can enclose a single line, though not required. It’s good practice for consistency and future code expansion.

Example:

if (condition) { 
    single_statement; 
}

if (condition) {

single_statement;

}

8. When “switch” is preferable over “if”

When testing a single variable against multiple constant values
For better readability with many conditions
When compiler can optimize with jump tables

Example:

switch(grade) {
    case 'A': printf("Excellent"); break;
    case 'B': printf("Good"); break;
    // More cases...
}

switch(grade) {

case 'A': printf("Excellent"); break;

case 'B': printf("Good"); break;

// More cases...

}

9. Preprocessor with example

The preprocessor processes source code before compilation. Directives begin with #.

Example:

#define PI 3.14159   // Defines a macro
#include <stdio.h>    // Includes header file
#ifdef DEBUG         // Conditional compilation
    printf("Debug mode");
#endif

#define PI 3.14159 // Defines a macro

#include <stdio.h> // Includes header file

#ifdef DEBUG // Conditional compilation

printf("Debug mode");

#endif

10. Bitwise operator

Operators that work on bits of integer types:

Operator	Meaning	Example
`&`	AND	`a & b`
		OR	`a`	b
`^`	XOR	`a ^ b`
`~`	NOT (flips bits)	`~a`
`<<`	Left shift	`a << 2`
`>>`	Right shift	`a >> 1`

Example usage:

unsigned char flags = 0x0A; // 00001010 in binary
flags = flags | 0x01;       // Set least significant bit (00001011)

1 2	unsigned char flags = 0x0A; // 00001010 in binary flags = flags \| 0x01; // Set least significant bit (00001011)

11. Program to find frequency of odd & even numbers in a matrix

#include <stdio.h>

int main() {
    int m, n, even = 0, odd = 0;
    
    printf("Enter matrix dimensions (m n): ");
    scanf("%d %d", &m, &n);
    
    int matrix[m][n];
    
    printf("Enter matrix elements:\n");
    for(int i = 0; i < m; i++) {
        for(int j = 0; j < n; j++) {
            scanf("%d", &matrix[i][j]);
            if(matrix[i][j] % 2 == 0)
                even++;
            else
                odd++;
        }
    }
    
    printf("Even numbers: %d\n", even);
    printf("Odd numbers: %d\n", odd);
    
    return 0;
}

#include <stdio.h>

int main() {

int m, n, even = 0, odd = 0;

printf("Enter matrix dimensions (m n): ");

scanf("%d %d", &m, &n);

int matrix[m][n];

printf("Enter matrix elements:\n");

for(int i = 0; i < m; i++) {

for(int j = 0; j < n; j++) {

scanf("%d", &matrix[i][j]);

if(matrix[i][j] % 2 == 0)

even++;

else

odd++;

}

printf("Even numbers: %d\n", even);

printf("Odd numbers: %d\n", odd);

return 0;

}

12. Program to check if first name contains only lowercase alphabets.

#include <stdio.h>
#include <ctype.h>
#include <stdbool.h>

bool isAllLowercase(const char *name) {
    while(*name) {
        if(!islower(*name) || !isalpha(*name))
            return false;
        name++;
    }
    return true;
}

int main() {
    char firstName[50];
    
    printf("Enter your first name: ");
    scanf("%s", firstName);
    
    if(isAllLowercase(firstName))
        printf("Valid: Only lowercase alphabets\n");
    else
        printf("Invalid: Contains non-lowercase characters\n");
    
    return 0;
}

#include <stdio.h>

#include <ctype.h>

#include <stdbool.h>

bool isAllLowercase(const char *name) {

while(*name) {

if(!islower(*name) || !isalpha(*name))

return false;

name++;

}

return true;

}

int main() {

char firstName[50];

printf("Enter your first name: ");

scanf("%s", firstName);

if(isAllLowercase(firstName))

printf("Valid: Only lowercase alphabets\n");

else

printf("Invalid: Contains non-lowercase characters\n");

return 0;

}

13. Program to draw a circle in C (using graphics.h)

#include <graphics.h>
#include <conio.h>

int main() {
    int gd = DETECT, gm;
    initgraph(&gd, &gm, "C:\\Turboc3\\BGI"); // Path may vary
    
    circle(300, 200, 100); // (x, y, radius)
    
    getch();
    closegraph();
    return 0;
}

#include <graphics.h>

#include <conio.h>

int main() {

int gd = DETECT, gm;

initgraph(&gd, &gm, "C:\\Turboc3\\BGI"); // Path may vary

circle(300, 200, 100); // (x, y, radius)

getch();

closegraph();

return 0;

}

14. Dynamic memory allocation functions

Check Notes of Your college

15. Commenting in C and debugging use

Comment types in C:

Single-line: // This is a comment
Multi-line: /* This is a multi-line comment */

Debugging with comments:

Temporarily commenting out code (instead of deleting) helps:
- Isolate problematic sections
- Test code incrementally
- Preserve original code for reference

// Original code
functionA();
// functionB();  // Temporarily disabled for testing
functionC();

// Original code

functionA();

// functionB(); // Temporarily disabled for testing

functionC();

16. Algorithm to check Armstrong number

Armstrong number: A number equal to the sum of its own digits each raised to the power of the number of digits.

Algorithm:

Input a number n
Store original number in temp
Calculate number of digits (d)
Initialize sum = 0
While n > 0:
- Extract last digit (digit = n % 10)
- Add digit^d to sum
- Remove last digit (n = n / 10)
If sum equals original number (temp)
- Print “Armstrong number”
Else
- Print “Not Armstrong number”

#include <stdio.h>
#include <math.h>

int main() {
    int n, original, digits = 0, sum = 0;
    
    printf("Enter a number: ");
    scanf("%d", &n);
    original = n;
    
    // Count number of digits
    for(int temp = original; temp != 0; digits++, temp /= 10);
    
    // Calculate sum of digits^d
    for(int temp = original; temp != 0; temp /= 10) {
        int digit = temp % 10;
        sum += pow(digit, digits);
    }
    
    if(sum == original)
        printf("%d is an Armstrong number\n", original);
    else
        printf("%d is not an Armstrong number\n", original);
    
    return 0;
}

#include <stdio.h>

#include <math.h>

int main() {

int n, original, digits = 0, sum = 0;

printf("Enter a number: ");

scanf("%d", &n);

original = n;

// Count number of digits

for(int temp = original; temp != 0; digits++, temp /= 10);

// Calculate sum of digits^d

for(int temp = original; temp != 0; temp /= 10) {

int digit = temp % 10;

sum += pow(digit, digits);

}

if(sum == original)

printf("%d is an Armstrong number\n", original);

else

printf("%d is not an Armstrong number\n", original);

return 0;

}

17. Program to sort array in descending order using pointers

#include <stdio.h>

void sortDescending(int *arr, int size) {
    for(int i = 0; i < size-1; i++) {
        for(int j = i+1; j < size; j++) {
            if(*(arr + i) < *(arr + j)) {
                // Swap using pointers
                int temp = *(arr + i);
                *(arr + i) = *(arr + j);
                *(arr + j) = temp;
            }
        }
    }
}

int main() {
    int arr[8];
    
    printf("Enter 8 integers:\n");
    for(int i = 0; i < 8; i++) {
        scanf("%d", arr + i); // Equivalent to &arr[i]
    }
    
    sortDescending(arr, 8);
    
    printf("Sorted array in descending order:\n");
    for(int i = 0; i < 8; i++) {
        printf("%d ", *(arr + i)); // Equivalent to arr[i]
    }
    
    return 0;
}

#include <stdio.h>

void sortDescending(int *arr, int size) {

for(int i = 0; i < size-1; i++) {

for(int j = i+1; j < size; j++) {

if(*(arr + i) < *(arr + j)) {

// Swap using pointers

int temp = *(arr + i);

*(arr + i) = *(arr + j);

*(arr + j) = temp;

}

int main() {

int arr[8];

printf("Enter 8 integers:\n");

for(int i = 0; i < 8; i++) {

scanf("%d", arr + i); // Equivalent to &arr[i]

}

sortDescending(arr, 8);

printf("Sorted array in descending order:\n");

for(int i = 0; i < 8; i++) {

printf("%d ", *(arr + i)); // Equivalent to arr[i]

}

return 0;

}

18. Palindrome Check

#include <stdio.h>
#include <string.h>
#include <stdbool.h>

bool isPalindrome(const char *str) {
    int left = 0;
    int right = strlen(str) - 1;
    
    while(left < right) {
        if(str[left] != str[right])
            return false;
        left++;
        right--;
    }
    return true;
}

int main() {
    char str[100];
    
    printf("Enter a string: ");
    scanf("%s", str);
    
    if(isPalindrome(str))
        printf("'%s' is a palindrome\n", str);
    else
        printf("'%s' is not a palindrome\n", str);
    
    return 0;
}

#include <stdio.h>

#include <string.h>

#include <stdbool.h>

bool isPalindrome(const char *str) {

int left = 0;

int right = strlen(str) - 1;

while(left < right) {

if(str[left] != str[right])

return false;

left++;

right--;

}

return true;

}

int main() {

char str[100];

printf("Enter a string: ");

scanf("%s", str);

if(isPalindrome(str))

printf("'%s' is a palindrome\n", str);

else

printf("'%s' is not a palindrome\n", str);

return 0;

}

19. Program to print the binary pattern

#include <stdio.h>

int main() {
    int rows;
    
    printf("Enter number of rows: ");
    scanf("%d", &rows);
    
    for(int i = 1; i <= rows; i++) {
        for(int j = 1; j <= i; j++) {
            printf("%d", j % 2); // Alternates between 1 and 0
        }
        printf("\n");
    }
    
    return 0;
}

#include <stdio.h>

int main() {

int rows;

printf("Enter number of rows: ");

scanf("%d", &rows);

for(int i = 1; i <= rows; i++) {

for(int j = 1; j <= i; j++) {

printf("%d", j % 2); // Alternates between 1 and 0

}

printf("\n");

}

return 0;

}

20. Program to find largest and smallest in array

#include <stdio.h>
#include <limits.h>

int main() {
    int n;
    
    printf("Enter number of elements: ");
    scanf("%d", &n);
    
    int arr[n];
    printf("Enter %d integers:\n", n);
    for(int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }
    
    int min = INT_MAX;
    int max = INT_MIN;
    
    for(int i = 0; i < n; i++) {
        if(arr[i] < min)
            min = arr[i];
        if(arr[i] > max)
            max = arr[i];
    }
    
    printf("Smallest element: %d\n", min);
    printf("Largest element: %d\n", max);
    
    return 0;
}

#include <stdio.h>

#include <limits.h>

int main() {

int n;

printf("Enter number of elements: ");

scanf("%d", &n);

int arr[n];

printf("Enter %d integers:\n", n);

for(int i = 0; i < n; i++) {

scanf("%d", &arr[i]);

}

int min = INT_MAX;

int max = INT_MIN;

for(int i = 0; i < n; i++) {

if(arr[i] < min)

min = arr[i];

if(arr[i] > max)

max = arr[i];

}

printf("Smallest element: %d\n", min);

printf("Largest element: %d\n", max);

return 0;

}

21. College Name Program

Program to store and display college name:

#include <stdio.h>
#include <string.h>

int main() {
    FILE *file;
    char college[100];
    
    // Write to file
    printf("Enter your college name: ");
    fgets(college, sizeof(college), stdin);
    college[strcspn(college, "\n")] = '\0'; // Remove newline
    
    file = fopen("a.txt", "w");
    if(file == NULL) {
        printf("Error creating file!\n");
        return 1;
    }
    fprintf(file, "%s", college);
    fclose(file);
    
    // Read from file
    file = fopen("a.txt", "r");
    if(file == NULL) {
        printf("Error opening file!\n");
        return 1;
    }
    
    printf("\nData read from file:\n");
    while(fgets(college, sizeof(college), file) != NULL) {
        printf("%s", college);
    }
    fclose(file);
    
    return 0;
}

#include <stdio.h>

#include <string.h>

int main() {

FILE *file;

char college[100];

// Write to file

printf("Enter your college name: ");

fgets(college, sizeof(college), stdin);

college[strcspn(college, "\n")] = '\0'; // Remove newline

file = fopen("a.txt", "w");

if(file == NULL) {

printf("Error creating file!\n");

return 1;

}

fprintf(file, "%s", college);

fclose(file);

// Read from file

file = fopen("a.txt", "r");

if(file == NULL) {

printf("Error opening file!\n");

return 1;

}

printf("\nData read from file:\n");

while(fgets(college, sizeof(college), file) != NULL) {

printf("%s", college);

}

fclose(file);

return 0;

}

22. Course Information Program:

#include <stdio.h>

struct Course {
    char course_code[10];
    char name[50];
    int credit_hour;
};

int main() {
    struct Course courses[5];
    
    // Input course data
    printf("Enter details for 5 courses:\n");
    for(int i = 0; i < 5; i++) {
        printf("\nCourse %d:\n", i+1);
        printf("Course Code: ");
        scanf("%s", courses[i].course_code);
        printf("Course Name: ");
        scanf(" %[^\n]", courses[i].name); // Reads entire line
        printf("Credit Hour: ");
        scanf("%d", &courses[i].credit_hour);
    }
    
    // Display courses with credit hour > 2
    printf("\nCourses with credit hour > 2:\n");
    for(int i = 0; i < 5; i++) {
        if(courses[i].credit_hour > 2) {
            printf("\nCourse Code: %s\n", courses[i].course_code);
            printf("Course Name: %s\n", courses[i].name);
            printf("Credit Hour: %d\n", courses[i].credit_hour);
        }
    }
    
    return 0;
}

#include <stdio.h>

struct Course {

char course_code[10];

char name[50];

int credit_hour;

};

int main() {

struct Course courses[5];

// Input course data

printf("Enter details for 5 courses:\n");

for(int i = 0; i < 5; i++) {

printf("\nCourse %d:\n", i+1);

printf("Course Code: ");

scanf("%s", courses[i].course_code);

printf("Course Name: ");

scanf(" %[^\n]", courses[i].name); // Reads entire line

printf("Credit Hour: ");

scanf("%d", &courses[i].credit_hour);

}

// Display courses with credit hour > 2

printf("\nCourses with credit hour > 2:\n");

for(int i = 0; i < 5; i++) {

if(courses[i].credit_hour > 2) {

printf("\nCourse Code: %s\n", courses[i].course_code);

printf("Course Name: %s\n", courses[i].name);

printf("Credit Hour: %d\n", courses[i].credit_hour);

}

return 0;

}

Notice

NCCS C 1st Sem Pre Board Solution

1. Difference between actual and formal parameters

2. Use of ftell() and rewind() functions

3. Four keywords of C

4. NULL pointer

5. When to use -> (arrow) operator

6. What’s wrong with: `name = "NCCS"`

7. Can { } be used for single line of code?

8. When “switch” is preferable over “if”

9. Preprocessor with example

10. Bitwise operator

11. Program to find frequency of odd & even numbers in a matrix

12. Program to check if first name contains only lowercase alphabets.

13. Program to draw a circle in C (using graphics.h)

14. Dynamic memory allocation functions

15. Commenting in C and debugging use

16. Algorithm to check Armstrong number

17. Program to sort array in descending order using pointers

18. Palindrome Check

19. Program to print the binary pattern

20. Program to find largest and smallest in array

Leave a Reply Cancel reply

Resources

Support Us

Join Group

1. Difference between actual and formal parameters

2. Use of ftell() and rewind() functions

3. Four keywords of C

4. NULL pointer

5. When to use -> (arrow) operator

6. What’s wrong with: name = "NCCS"

7. Can { } be used for single line of code?

8. When “switch” is preferable over “if”

9. Preprocessor with example

10. Bitwise operator

11. Program to find frequency of odd & even numbers in a matrix

12. Program to check if first name contains only lowercase alphabets.

13. Program to draw a circle in C (using graphics.h)

14. Dynamic memory allocation functions

15. Commenting in C and debugging use

16. Algorithm to check Armstrong number

17. Program to sort array in descending order using pointers

18. Palindrome Check

19. Program to print the binary pattern

20. Program to find largest and smallest in array

Leave a Reply Cancel reply

Resources

Support Us

Join Group

6. What’s wrong with: `name = "NCCS"`