PPS 2023 BEU PYQ Solution – Programming For Problem solving Previous Year Questions with Answers

PPS 2023 BEU PYQ Solution,1st Semester PPS Examination, 2023

Question 1

Choose the correct answer of the following (Any seven questions only):

(a) What is the output of the following code?

int x = 10;
x++;
printf("%d", x);

1. Error
2. 10
3. 11
4. 9

Answer: (3) 11

(b) Which function is used to dynamically allocate memory in C?

1. malloc()
2. calloc()
3. realloc()
4. all of the above

Answer: (4) all of the above

(c) What is the output of the following code?

#include<stdio.h>
int main() {
    char *p = 0;
    *p = 'a';
    printf("%c", *p);
    return 0;
}

1. It will print ‘a’
2. It will print 0
3. Compile time error
4. Runtime error

Answer: (4) Runtime error

(d) What are the elements present in the array of the following C code?

int array[6] = {5};

1. 5, 5, 5, 5, 5, 5
2. 5, 0, 0, 0, 0, 0
3. 6, 6, 6, 6, 6, 6
4. (garbage), (garbage), (garbage), (garbage), (garbage), 5

Answer: (2) 5, 0, 0, 0, 0, 0

(e) What will be the output of the following C code?

void main(){
    int i = 0;
    while (i < 10){
        i++;
        printf("hi\n");
        while (i < 8){
            i++;
        }
        printf("hello\n");
    }
}

1. hi is printed 8 times, hello 7 times and then hi 2 times
2. hi is printed once, hello 7 times
3. hi is printed once, hello 7 times and then hi 2 times
4. None of the above

Answer: (3) hi is printed once, hello 7 times and then hi 2 times

(f) What does the following declaration mean?

int (*ptr) [10];

1. ptr is array of pointers to 10 integers.
2. ptr is a pointer to an array of 10 integers.
3. ptr is an array of 10 integers.
4. ptr is a pointer to array of 10 characters.

Answer: (2) ptr is a pointer to an array of 10 integers.

(g) C is ________ type of programming language?

1. Object Oriented
2. Procedural
3. Bit level language
4. Functional

Answer: (2) Procedural

(h) Choose the right C statement.

1. int my age = 10;
2. int my.age = 10;
3. int my_age = 10;
4. All are correct

Answer: (3) int my_age = 10;

Question 2

(a) Explain the difference between auto and static type storage variables with suitable example codes.

Answer:

the difference between auto and static storage type variables, along with example codes:

(b) Differentiate between structures and unions in C. Write a C program to detect whether the computer is little endian or big endian using unions.

Answer: Difference Between Structures and Unions in C :

C program that detects whether a computer is little-endian or big-endian using a union:

#include <stdio.h>

union EndianCheck {
    int num;
    char byte;
};

void checkEndianness() {
    union EndianCheck e;
    e.num = 1;

    if (e.byte == 1)
        printf("System is Little Endian\n");
    else
        printf("System is Big Endian\n");
}

int main() {
    checkEndianness();
    return 0;
}

Question 3

(a) Write an efficient C program to search if the integer 24 is present in the given sorted array or not. If it is present, print the index where it is found.

Answer:

To efficiently search for an integer in a sorted array, we can use Binary Search, which has a time complexity of O(log n). Here’s the C program to check if 24 is present in a sorted array and print its index if found.

C Program (Binary Search)

#include <stdio.h>

// Function to perform Binary Search
int binarySearch(int arr[], int left, int right, int key) {
    while (left <= right) {
        int mid = left + (right - left) / 2; // Avoids integer overflow

        // Check if key is at mid
        if (arr[mid] == key)
            return mid;

        // If key is greater, search in right half
        if (arr[mid] < key)
            left = mid + 1;
        else // If key is smaller, search in left half
            right = mid - 1;
    }
    return -1; // Key not found
}

int main() {
    int arr[] = {1, 5, 8, 12, 15, 19, 24, 30, 35, 40}; // Sorted array
    int size = sizeof(arr) / sizeof(arr[0]);
    int key = 24; // Number to search

    int result = binarySearch(arr, 0, size - 1, key);

    if (result != -1)
        printf("Element %d found at index %d\n", key, result);
    else
        printf("Element %d not found in the array\n", key);

    return 0;
}

Explanation:

1. Binary Search Logic:
   • Start with the middle element.
   • If key == mid, return the index.
   • If key > mid, search in the right half.
   • If key < mid, search in the left half.
   • Repeat the process until left > right.
2. Time Complexity:
   • Binary Search: O(log n)
   • Much faster than Linear Search (O(n)) for large arrays.
3. Output (if 24 is present in the array): Element 24 found at index 6

(b) Explain the insertion sort algorithm and its steps using an example. Consider the array: [5, 2, 4, 6, 1, 3].

Answer:

Insertion Sort Algorithm

Insertion Sort is a simple sorting algorithm that builds a sorted list one element at a time. It is efficient for small datasets and nearly sorted data.

How Insertion Sort Works?

1. Assume the first element is already sorted.
2. Pick the next element and compare it with the elements in the sorted part.
3. Shift all larger elements one position to the right to create space.
4. Insert the picked element at its correct position.
5. Repeat the process for all elements until the array is fully sorted.

Example: Sorting [5, 2, 4, 6, 1, 3] using Insertion Sort

Step-by-Step Execution:

Final Sorted Array: [1, 2, 3, 4, 5, 6]

Time Complexity Analysis:

• Best Case (Already Sorted): O(n)
• Worst Case (Reverse Sorted): O(n²)
• Average Case: O(n²)

C Program for Insertion Sort

C program to implement Insertion Sort and sort an array.

#include <stdio.h>

// Function to perform Insertion Sort
void insertionSort(int arr[], int n) {
    for (int i = 1; i < n; i++) {
        int key = arr[i];  // Current element to insert
        int j = i - 1;

        // Shift elements of sorted part that are greater than key
        while (j >= 0 && arr[j] > key) {
            arr[j + 1] = arr[j];
            j--;
        }
        
        arr[j + 1] = key; // Insert key at the correct position
    }
}

// Function to print the array
void printArray(int arr[], int n) {
    for (int i = 0; i < n; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");
}

int main() {
    int arr[] = {5, 2, 4, 6, 1, 3}; 
    int n = sizeof(arr) / sizeof(arr[0]);

    printf("Original array: ");
    printArray(arr, n);

    insertionSort(arr, n);

    printf("Sorted array: ");
    printArray(arr, n);

    return 0;
}

Question 4

(a) Describe the concept of pointers in C programming language. Explain how pointers work and discuss their importance in programming, particularly in memory management and efficient data manipulation.

Answer: Understanding Pointers in C

A pointer is a special variable in C that stores the memory address of another variable. Instead of storing actual values, pointers store the location of values in memory.

How Do Pointers Work?

1. Every variable in C is stored in memory with a specific address.
2. A pointer holds the address of a variable rather than the actual value.
3. Using pointers, we can access and modify the variable indirectly.

Declaring and Using Pointers

To declare a pointer, use the * (asterisk) symbol.

int num = 10;  // Normal variable
int *ptr = #  // Pointer storing the address of num

• num is an integer variable storing the value 10.
• ptr is a pointer variable storing the address of num (&num gives the address).

Dereferencing a Pointer

We use * to access the value stored at the memory address a pointer holds.

printf("%d", *ptr);  // Output: 10 (value at the address stored in ptr)

Why Are Pointers Important?

1. Memory Management

• Pointers allow direct access to memory locations.
• They are essential for dynamic memory allocation using malloc() and free().

2. Efficient Data Manipulation

• Instead of copying large amounts of data, we can use pointers to access data directly.
• Helps in functions where passing by reference avoids unnecessary copying.

3. Working with Arrays and Strings

• Arrays and pointers are closely related.
• Strings in C are often manipulated using pointers.

4. Creating Complex Data Structures

• Used in linked lists, trees, graphs, and other dynamic structures.

Example: Pointers and Functions

#include <stdio.h>

// Function to modify value using pointer
void modifyValue(int *ptr) {
    *ptr = 20;  // Change value at the memory location
}

int main() {
    int num = 10;
    printf("Before: %d\n", num);

    modifyValue(&num);  // Pass address of num
    printf("After: %d\n", num);

    return 0;
}

Output:

Before: 10  
After: 20  

Explanation: The function modifies the actual value of num using a pointer.

(b) Write a C program to copy contents of one file to another. While doing so replace all lowercase characters to their equivalent uppercase characters.

Answer:

C Program to Copy Contents of One File to Another and Convert Lowercase to Uppercase

This program reads the contents of a file, converts lowercase letters to uppercase, and writes the modified content into another file.

C Code:

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

int main() {
    FILE *src, *dest;
    char ch;

    // Open source file in read mode
    src = fopen("input.txt", "r");
    if (src == NULL) {
        printf("Error opening input file.\n");
        return 1;
    }

    // Open destination file in write mode
    dest = fopen("output.txt", "w");
    if (dest == NULL) {
        printf("Error creating output file.\n");
        fclose(src);
        return 1;
    }

    // Read, convert, and write
    while ((ch = fgetc(src)) != EOF) {
        fputc(toupper(ch), dest);
    }

    // Close files
    fclose(src);
    fclose(dest);

    printf("File copied successfully.\n");

    return 0;
}

Example Usage:

Input File (input.txt)

Hello World!
This is a Test file.

Output File (output.txt)

HELLO WORLD!
THIS IS A TEST FILE.

Question 5

(a) Write a C program to find the Euclidean distance between two points P(x, y) and Q(a, b) using structure representation of points P and Q.

Answer:

C Program to Find Euclidean Distance Between Two Points Using Structures

The Euclidean distance between two points P(x, y) and Q(a, b) is given by the formula:

C Code:

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

// Define a structure for a point
struct Point {
    float x, y;
};

// Function to calculate Euclidean distance
float euclideanDistance(struct Point p, struct Point q) {
    return sqrt(pow(q.x - p.x, 2) + pow(q.y - p.y, 2));
}

int main() {
    struct Point P, Q;
    float distance;

    // Input coordinates for point P
    printf("Enter coordinates of point P (x y): ");
    scanf("%f %f", &P.x, &P.y);

    // Input coordinates for point Q
    printf("Enter coordinates of point Q (a b): ");
    scanf("%f %f", &Q.x, &Q.y);

    // Calculate distance
    distance = euclideanDistance(P, Q);

    // Display result
    printf("Euclidean Distance: %.2f\n", distance);

    return 0;
}

Input:

Enter coordinates of point P (x y): 3 4
Enter coordinates of point Q (a b): 7 1

Output:

Euclidean Distance: 5.00

(b) Differentiate between call-by-value and call-by-reference with suitable examples.

Answer:

In C programming, functions can be called in two ways:

1. Call by Value: A copy of the variable is passed.
2. Call by Reference: The actual address of the variable is passed.

Example of Call by Value

#include <stdio.h>

// Function using call by value
void modify(int num) {
    num = 20;  // Change inside function
    printf("Inside function: %d\n", num);
}

int main() {
    int num = 10;
    modify(num);  // Passing a copy of num
    printf("Outside function: %d\n", num);  // Original value remains unchanged
    return 0;
}

Output:

Inside function: 20
Outside function: 10

Here, the original value of num remains unchanged because only a copy was modified.

Example of Call by Reference

#include <stdio.h>

// Function using call by reference
void modify(int *num) {
    *num = 20;  // Modify original variable using pointer
    printf("Inside function: %d\n", *num);
}

int main() {
    int num = 10;
    modify(&num);  // Passing address of num
    printf("Outside function: %d\n", num);  // Original value is changed
    return 0;
}

Output:

Inside function: 20
Outside function: 20

Here, the original value of num changes because we passed its address

Question 6

(a) Define arrays in C and explain their declaration and usage. Write a C program to reverse the content of an integer array without using auxiliary array.

Answer:

Arrays in C

An array is a collection of elements of the same data type stored in contiguous memory locations. It allows storing multiple values under a single variable name and accessing them using an index.

Declaration of Arrays in C

An array can be declared as:

data_type array_name[size];

Example:

int numbers[5];  // Declares an array of 5 integers

You can also initialize an array at the time of declaration:

int numbers[5] = {1, 2, 3, 4, 5};  // Declares and initializes an array

Usage of Arrays

1. Accessing Elements: printf("%d", numbers[2]); // Accesses the 3rd element (index 2)
2. Modifying Elements: numbers[1] = 10; // Changes the second element to 10
3. Iterating Over an Array: for(int i = 0; i < 5; i++) { printf("%d ", numbers[i]); // Prints array elements }

C Program to Reverse an Integer Array (Without Using Auxiliary Array)

#include <stdio.h>

// Function to reverse an array
void reverseArray(int arr[], int size) {
    int start = 0, end = size - 1;
    
    while (start < end) {
        // Swap elements at start and end
        int temp = arr[start];
        arr[start] = arr[end];
        arr[end] = temp;
        
        // Move towards the center
        start++;
        end--;
    }
}

int main() {
    int arr[] = {1, 2, 3, 4, 5};
    int size = sizeof(arr) / sizeof(arr[0]);

    printf("Original Array: ");
    for(int i = 0; i < size; i++) {
        printf("%d ", arr[i]);
    }

    // Reverse the array
    reverseArray(arr, size);

    printf("\nReversed Array: ");
    for(int i = 0; i < size; i++) {
        printf("%d ", arr[i]);
    }

    return 0;
}

Output:

Original Array: 1 2 3 4 5 
Reversed Array: 5 4 3 2 1

(b) Define implicit and explicit type casting in C. Provide code examples illustrating when each type of casting occurs and their potential side effects.

Answer:

Implicit and Explicit Type Casting in C

Implicit Type Casting (Automatic Conversion)

Implicit type casting happens automatically when a smaller data type is converted into a larger one. The compiler does this to prevent data loss.

Example of Implicit Type Casting

#include <stdio.h>

int main() {
    int num = 10;
    float result = num;  // int is automatically converted to float

    printf("Implicit Casting: %f\n", result);  // Output: 10.000000
    return 0;
}

It happens when:

• Assigning a smaller type to a larger type (e.g., int to float).
• Performing arithmetic operations between different types (int + float).

Side Effect

It may cause loss of precision when converting an integer to a float.

Explicit Type Casting (Manual Conversion)

Explicit type casting is done manually using the (type) operator. It forces a value to change its type.

Example of Explicit Type Casting

#include <stdio.h>

int main() {
    float num = 10.75;
    int result = (int)num;  // float is manually converted to int

    printf("Explicit Casting: %d\n", result);  // Output: 10
    return 0;
}

When is it used?

• When we need to control type conversion
• To convert float to int (removing decimal values)
• To fix integer division issues

Example: Fixing Integer Division

#include <stdio.h>

int main() {
    int a = 5, b = 2;
    float result = (float)a / b;  // Convert 'a' to float before division

    printf("Correct Division: %f\n", result);  // Output: 2.500000
    return 0;
}

Side Effect

Can remove decimal values, leading to data loss (e.g., 10.75 → 10).

Question 7

(a) Explain the concept of nested loops. Describe how the break and continue statements alter the flow of control within C loops.

Answer:

Nested Loops in C

A nested loop is a loop inside another loop. The inner loop runs completely for each iteration of the outer loop.

Example

#include <stdio.h>

int main() {
    for (int i = 1; i <= 3; i++) {  
        for (int j = 1; j <= 3; j++) {  
            printf("(%d, %d) ", i, j);
        }
        printf("\n");
    }
    return 0;
}

Output

(1, 1) (1, 2) (1, 3)  
(2, 1) (2, 2) (2, 3)  
(3, 1) (3, 2) (3, 3)  

Break and Continue in Loops

Break Statement

• Exits the loop immediately when a condition is met.

Example

for (int i = 1; i <= 5; i++) {
    if (i == 3) break;
    printf("%d ", i);
}

Output: 1 2

Continue Statement

• Skips the current iteration and moves to the next one.

Example

for (int i = 1; i <= 5; i++) {
    if (i == 3) continue;
    printf("%d ", i);
}

Output: 1 2 4 5

Important point:

✔ Nested loops repeat actions inside another loop.
✔ Break stops the loop completely.
✔ Continue skips one iteration but keeps looping.

(b) Explain the concept of algorithmic complexity and its significance in computer science. Using examples, illustrate how different algorithms exhibit various orders of complexity, such as constant time (O(1)), linear time (O(n)), logarithmic time (O(log n)), quadratic time (O(n²)), and exponential time (O(2ⁿ)).

Answer:

Algorithmic Complexity and Its Importance

Algorithmic complexity measures how an algorithm’s performance changes as input size increases. It helps in understanding efficiency and optimizing programs.

Types of Complexity with Examples

1. Constant Time – O(1)

Execution time does not change with input size.
Example: Accessing an element in an array.

int getFirstElement(int arr[]) {
    return arr[0];  // Always takes constant time
}

2. Linear Time – O(n)

Execution time grows proportionally with input size.
Example: Searching an element in an array.

int search(int arr[], int n, int key) {
    for (int i = 0; i < n; i++) {
        if (arr[i] == key)
            return i;  
    }
    return -1;  
}

3. Logarithmic Time – O(log n)

Execution time grows slowly as input increases.
Example: Binary search in a sorted array.

int binarySearch(int arr[], int left, int right, int key) {
    while (left <= right) {
        int mid = left + (right - left) / 2;
        if (arr[mid] == key)
            return mid;
        else if (arr[mid] < key)
            left = mid + 1;
        else
            right = mid - 1;
    }
    return -1;
}

4. Quadratic Time – O(n²)

Execution time grows quadratically with input size.
Example: Bubble Sort algorithm.

void bubbleSort(int arr[], int n) {
    for (int i = 0; i < n - 1; i++) {
        for (int j = 0; j < n - i - 1; j++) {
            if (arr[j] > arr[j + 1]) {
                int temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
            }
        }
    }
}

5. Exponential Time – O(2ⁿ)

Execution time doubles with each increase in input size.
Example: Recursive Fibonacci calculation.

int fibonacci(int n) {
    if (n <= 1)
        return n;
    return fibonacci(n - 1) + fibonacci(n - 2);
}

Important points:

✔ O(1) (Constant Time) – Fastest, ideal for efficiency.
✔ O(n) (Linear Time) – Grows proportionally with input size.
✔ O(log n) (Logarithmic Time) – Used in binary search, efficient for large data.
✔ O(n²) (Quadratic Time) – Slow for large data, common in nested loops.
✔ O(2ⁿ) (Exponential Time) – Very slow, used in recursion.

Question 8

(a) The first 6 numbers of the Fibonacci series are: 0 1 1 2 3 5. Write a C program using recursion to find and print the Fibonacci series for first n terms.

Answer:

This is a simple C program using recursion to print the Fibonacci series for the first n terms:

#include <stdio.h>

// Function to find Fibonacci number using recursion
int fibonacci(int n) {
    if (n <= 0) 
        return 0;
    else if (n == 1) 
        return 1;
    else 
        return fibonacci(n - 1) + fibonacci(n - 2);
}

int main() {
    int n;
    printf("Enter the number of terms: ");
    scanf("%d", &n);

    printf("Fibonacci Series: ");
    for (int i = 0; i < n; i++) {
        printf("%d ", fibonacci(i));
    }
    return 0;
}

Example Output

Enter the number of terms: 6  
Fibonacci Series: 0 1 1 2 3 5  

(b) Write a C program using recursion to find factorial of a given number n.

Answer:

This is a simple C program using recursion to find the factorial of a given number n:

#include <stdio.h>

// Function to calculate factorial using recursion
long long factorial(int n) {
    if (n == 0 || n == 1)  
        return 1;  // Base case
    else  
        return n * factorial(n - 1);  // Recursive case
}

int main() {
    int n;
    printf("Enter a number: ");
    scanf("%d", &n);

    if (n < 0)
        printf("Factorial is not defined for negative numbers.\n");
    else
        printf("Factorial of %d is %lld\n", n, factorial(n));

    return 0;
}

Example Output

Enter a number: 5  
Factorial of 5 is 120  

Question 9

(a) Write a C program for the following:

(i) Reverse a string without using strrev().

Answer:

This is a simple C program to reverse a string without using strrev():

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

// Function to reverse a string
void reverseString(char str[]) {
    int left = 0, right = strlen(str) - 1;
    while (left < right) {
        // Swap characters
        char temp = str[left];
        str[left] = str[right];
        str[right] = temp;
        left++;
        right--;
    }
}

int main() {
    char str[100];

    printf("Enter a string: ");
    scanf("%s", str);  // Reads a single word

    reverseString(str);
    printf("Reversed string: %s\n", str);

    return 0;
}

Example Output

Enter a string: hello  
Reversed string: olleh  

(ii) Concatenate two strings without using strcat().

Answer:

This is a simple C program to concatenate two strings without using strcat():

#include <stdio.h>

void concatenate(char str1[], char str2[]) {
    int i = 0, j = 0;
    while (str1[i] != '\0') i++;  // Find end of str1
    while ((str1[i++] = str2[j++]) != '\0');  // Append str2
}

int main() {
    char str1[100], str2[100];
    printf("Enter first string: ");
    scanf("%s", str1);
    printf("Enter second string: ");
    scanf("%s", str2);
    concatenate(str1, str2);
    printf("Concatenated string: %s\n", str1);
    return 0;
}

Example Output

Enter first string: Hello  
Enter second string: World  
Concatenated string: HelloWorld  

(b) Write a C program to find result matrix after multiplying two given matrices using 2-D arrays. Check the multiplication criteria also while deriving the logic.

Answer:

This is a C program to multiply two matrices using 2-D arrays, while also checking the multiplication criteria:

#include <stdio.h>

int main() {
    int a[10][10], b[10][10], result[10][10] = {0}, r1, c1, r2, c2;

    printf("Enter rows and columns of first matrix: ");
    scanf("%d %d", &r1, &c1);
    printf("Enter rows and columns of second matrix: ");
    scanf("%d %d", &r2, &c2);

    if (c1 != r2) {
        printf("Matrix multiplication not possible.\n");
        return 0;
    }

    printf("Enter first matrix:\n");
    for (int i = 0; i < r1; i++)
        for (int j = 0; j < c1; j++)
            scanf("%d", &a[i][j]);

    printf("Enter second matrix:\n");
    for (int i = 0; i < r2; i++)
        for (int j = 0; j < c2; j++)
            scanf("%d", &b[i][j]);

    // Matrix multiplication
    for (int i = 0; i < r1; i++)
        for (int j = 0; j < c2; j++)
            for (int k = 0; k < c1; k++)
                result[i][j] += a[i][k] * b[k][j];

    printf("Resultant matrix:\n");
    for (int i = 0; i < r1; i++) {
        for (int j = 0; j < c2; j++)
            printf("%d ", result[i][j]);
        printf("\n");
    }

    return 0;
}

How It Works?

✔ Takes input for both matrices.
✔ Checks if multiplication is possible (c1 == r2).
✔ Uses nested loops to multiply matrices.
✔ Prints the resultant matrix.

Example Output

Enter rows and columns of first matrix: 2 2  
Enter rows and columns of second matrix: 2 2  
Enter first matrix:  
1 2  
3 4  
Enter second matrix:  
5 6  
7 8  
Resultant matrix:  
19 22  
43 50  

 Conclusion:

In this post, we provided detailed solutions for BEE 2023 PPS (Programming for Problem Solving) previous year questions. Understanding these solutions will help you strengthen your core concepts and improve your exam performance. Keep practicing and exploring related topics to enhance your knowledge.

 You May Also Like:

• BEU PYQ Solutions – Explore More Previous Year Questions
• Programming for Problem Solving PYQ Solutions – BEU
• NPTEL Assignment Solutions – Latest Updates

 Stay Updated – Join Our Community:

 Never miss an update! Join our WhatsApp group to receive the latest PYQ solutions, NPTEL answers, and study resources directly on your phone.
 Join Now – PrabhakarGuru Updates

 Disclaimer:

The solutions provided here are based on our best knowledge and are for educational purposes only. We encourage students to refer to their official study materials and consult their professors for further clarification.