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Day 3 : Questions list

Posted on December 17, 2023January 1, 2024 By thecodepathshala No Comments on Day 3 : Questions list

Simple if, if-else, nested if-else and else-if ladder

  • Take two int values from user and print greatest among them using if/else and ternary operator.
#include <stdio.h>

int main()
{
    int num1, num2;
    printf("Enter num1\n");
    scanf("%d", &num1);
    printf("Enter num2\n");
    scanf("%d", &num2);
    printf("Using if else : \n");
    if (num1 > num2)
    {
        printf("%d is greater number\n",num1);
    }
    else
    {
        printf("%d is greater number\n",num2);
    }

    // Ternary operator
    printf("Using ternary operator : \n");
    (num1 > num2) ? printf("%d is greater number\n",num1) : printf("%d is greater number\n",num2);
    return 0;
}
  • Take values of length and breadth of a rectangle from user and check if it is square or not.
#include <stdio.h>

int main()
{
    int length, breadth;
    printf("Enter length\n");
    scanf("%d", &length);
    printf("Enter breadth\n");
    scanf("%d", &breadth);
    if (length == breadth)
    {
        printf("It is a square\n");
    }
    else
    {
        printf("It is a rectangle\n");
    }
    return 0;
}
  • A shop will give discount of 10% if the cost of purchased quantity is more than 1000. Ask user for quantity Suppose, one unit will cost 100. Judge and print total cost for user.
#include <stdio.h>

int main()
{
    int quantity, price, discount;
    printf("Enter quantity\n");
    scanf("%d", &quantity);
    price = quantity * 100;
    if (price > 1000) {
        discount = price * 0.1;
        printf("Total cost is %d\n", price - discount);
    }
    else {
        printf("Total cost is %d\n", price);
    }
    return 0;
}

/*
Output :
Enter quantity
20
if Total cost is 1800
*/
  • A company decided to give bonus of 5% to employee if his/her year of service is more than 5 years. Ask user for their salary and year of service and print the net bonus amount.

  • A school has following rules for grading system:
    a. Below 25 – F
    b. 25 to 45 – E
    c. 45 to 50 – D
    d. 50 to 60 – C
    e. 60 to 80 – B
    f. Above 80 – A
    Ask user to enter marks and print the corresponding grade.
#include <stdio.h>

int main()
{
    int marks;
    printf("Enter marks\n");
    scanf("%d", &marks);
    if (marks < 25){
        printf("F\n");
    }
    else if(marks >=25 && marks <45){
        printf("E\n");
    }
    else if(marks >=45 && marks <50){
        printf("D\n");
    }
    else if(marks >=50 && marks <60){
        printf("C\n");
    }
    else if(marks >=60 && marks <80){
        printf("B\n");
    }
    else if(marks >=80 && marks <100){
        printf("A\n");
    }
    else{
        printf("Invalid marks\n");
    }
    return 0;
}

/*
Output :

Enter marks
65
B

Enter marks
30
E

Enter marks
20
F
*/
  • Take input of age of 3 people by user and determine oldest and youngest among them.

  • A student will not be allowed to sit in exam if his/her attendence is less than 75%.
    Take following input from user
    Number of classes held
    Number of classes attended.
    And print
    percentage of class attended
    Is student is allowed to sit in exam or not.

  • A student will not be allowed to sit in exam if his/her attendence is less than 75%.
    Take following input from user
    Number of classes held
    Number of classes attended.
    And print
    percentage of class attended
    Is student is allowed to sit in exam or not.
    Modify this question to allow student to sit if he/she has medical cause. Ask user if he/she has medical cause or not ( ‘Y’ or ‘N’ ) and print accordingly.

  • Write a program to check whether a entered character is lowercase ( a to z ) or uppercase ( A to Z ).

  • If
    x = 2
    y = 5
    z = 0
    then find values of the following expressions:
    a. x == 2
    b. x != 5
    c. x != 5 && y >= 5
    d. z != 0 || x == 2
    e. !(y < 10)
  • Write a program to print absolute vlaue of a number entered by user.
#include <stdio.h>

int main()
{
    int x;
    printf("Enter a number\n");
    scanf("%d", &x);
    if (x < 0)
    {
        x = x * (-1);
    }
    printf("Absolute value is %d\n", x);
    return 0;
}

/*
Output :

Enter a number
2
Absolute value is 2

Enter a number
-2
Absolute value is 2
*/
  • C program to check Leap Year
  • C program to find maximum between three numbers
  • C program to check positive, negative or zero using simple if or if else
  • C program check whether a number is even or odd
  • C program to check whether a character is alphabet or not
  • C program to check vowel or consonant
  • C program to check whether a character is alphabet, digit or special character
  • C program to check whether a character is Uppercase or Lowercase
  • C program to enter week number and print day of week
  • C program to find number of days in month
  • C program to count total number of notes in given amount
  • C program to check whether triangle is valid or not if angles are given
  • C program to check whether triangle is valid or not if sides are given
  • C program to check whether triangle is equilateral, scalene or isosceles
  • C program to find all roots of a quadratic equation
  • C program to calculate profit or loss
  • C program to enter student marks and find percentage and grade

List of switch case programming exercises

  1. C program to print day of week name using switch case
  2. C program to print number of days in a month using switch case
  3. C program to check vowel or consonant using switch case
  4. C program to find maximum between two numbers using switch case
  5. C program to check even or odd number using switch case
  6. C program to check positive negative or zero using switch case
  7. C program to find all roots of a quadratic equation using switch case
  8. C program to create calculator using switch case and functions

Programs on loops

  1. C program to print all natural numbers from 1 to n using while loop
  2. C program to print natural numbers in reverse from n to 1
  3. C program to print all alphabets from a to z using while loop
  4. C program to print all even numbers from 1 to n
  5. C program to print all odd numbers from 1 to n
  6. C program to find sum of natural numbers from 1 to n
  7. C program to find sum of even numbers between 1 to n
  8. C program to find sum of odd numbers from 1 to n
  9. C program to print multiplication table of a given number
  10. C program to count number of digits in an integer
  11. C program to find first and last digit of any number
  12. C program to find sum of digits of a number
  13. C program to find reverse of a number
  14. C program to check whether a number is palindrome or not
  15. C program to count frequency of digits in an integer
  16. C program to print number in words
  17. C program to print ASCII values of all characters
  18. C program to find power of a number using for loop
  19. C program to find all factors of a number
  20. C program to find factorial of a number
  21. C program to find HCF (GCD) of two numbers
  22. C program to find LCM of two numbers
  23. C program to check whether a number is prime number or not
  24. C program to print all prime numbers between 1 to n
  25. C program to find prime factors of a number
  26. C program to check whether a number is armstrong number or not
  27. C program to check whether a number is perfect number or not
  28. C program to find perfect numbers between 1 to n
  29. C program to check whether a number is Strong number or not
  30. C program to print strong numbers between 1 to n
  31. C program to print fibonacci series upto n terms
  32. C program to find ones complement of a binary number
  33. C program to find twos complement of a binary number
  34. C program to convert Binary to Decimal number system
  35. C program to convert Binary to Octal number system
  36. C program to convert Binary to Hexadecimal number system
  37. C program to convert Octal to Binary number system
  38. C program to convert Octal to Decimal number system
  39. C program to convert Octal to Hexadecimal number system
  40. C program to convert Decimal to Binary number system
  41. C program to convert Decimal to Octal number system
  42. C program to convert Decimal to Hexadecimal number system
  43. C program to convert Hexadecimal to Binary number system
  44. C program to convert Hexadecimal to Octal number system
  45. C program to convert Hexadecimal to Decimal number system
  46. C program to print pascal triangle
  47. C program to print hollow right triangle star pattern

Mastering in C programming (Crash Course) Tags:Mastering C Programming in 15 Days

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Lekin kya aapko actually pata hai ki Vector internally kaise kaam karta hai?

Normal array aur vector mein actual difference kya hai?

size() aur capacity() alag kyun hote hain?

push_back() ke peeche kya hota hai?

Aur sabse important — reserve() aur resize() mein kya difference hai?

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In this video, we'll understand:

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✅ push_back()
✅ pop_back()
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✅ clear()
✅ empty()
✅ front() / back()
✅ operator[]
✅ Iteration
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✅ Interview-oriented Vector usage

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size() → Vector mein currently kitne elements hain.

capacity() → Current allocated storage mein maximum kitne elements fit ho sakte hain without another allocation.

Example:

vector[int] v;

v.push_back(10);
v.push_back(20);
v.push_back(30);

cout - v.size();
cout - v.capacity();

Size aur capacity ka difference samajhna vector ke internal working ko samajhne ke liye extremely important hai.

⚡ push_back() INTERNALLY KYA KARTA HAI?

Jab vector ke paas extra capacity hoti hai, push_back() new element ko available storage mein add kar deta hai.

Lekin jab:

size == capacity

toh vector ko larger memory block allocate karke existing elements ko move/copy karna pad sakta hai. Isi wajah se individual reallocation expensive ho sakti hai, although push_back() ka amortized complexity O(1) hota hai.

🚀 reserve() vs resize()

reserve(n)
→ Future growth ke liye capacity reserve karta hai.
→ Existing size ko change nahi karta.

resize(n)
→ Vector ke actual number of elements ko change karta hai.
→ Elements add ya remove ho sakte hain.

Ye dono functions coding interviews mein frequently confuse kiye jaate hain.

🎯 VECTOR INDEXING O(1) KYUN HAI?

Vector elements contiguous memory mein store hote hain.

Isliye:

v[i]

ko direct address calculation ke through access kiya ja sakta hai.

Conceptually:

address = base_address + i × sizeof(element)

Isi wajah se vector random access O(1) provide karta hai.

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🔥 Sliding Window
🔥 Prefix Sum
🔥 Sorting Problems
🔥 Binary Search
🔥 Two Pointers
🔥 Matrix / 2D Vector
🔥 Dynamic Programming
🔥 Graph Representation
🔥 Frequency Arrays
🔥 LeetCode Problems

Agar aap C++ mein DSA kar rahe hain, toh Vector ko sirf ek STL function nahi, balki dynamic array ke concept ke roop mein samajhna bahut important hai.

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💬 Comment karein: size() aur capacity() mein difference pehle pata tha?

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✅ Vector
✅ Pair
✅ List
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✅ Queue
✅ Priority Queue
✅ Set
✅ Map
✅ Unordered Map / Set
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✅ sort()
✅ reverse()
✅ find()
✅ binary_search()
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