All C++ practical programs for Semester 1

// 1. Print "Hello World" 5 times #include using namespace std; int main() { for(int i = 1; i <= 5; i++) { cout << "Hello World" << endl; } return 0; }

// 2. Test whether a given number is Odd or Even #include using namespace std; int main() { int num; cout << "Enter a number: "; cin >> num;

if(num % 2 == 0)
    cout << num << " is Even";
else
    cout << num << " is Odd";
return 0;

}

// 3. Print a simple pattern (right-angled triangle) #include using namespace std; int main() { int n; cout << "Enter number of rows: "; cin >> n;

for(int i = 1; i <= n; i++) {
    for(int j = 1; j <= i; j++) {
        cout << "* ";
    }
    cout << endl;
}
return 0;

}

// 4. Check if a string is Palindrome #include #include using namespace std; int main() { string str, rev = ""; cout << "Enter a string: "; cin >> str;

for(int i = str.length() - 1; i >= 0; i--) {
    rev += str[i];
}

if(str == rev)
    cout << "Palindrome String";
else
    cout << "Not a Palindrome";
return 0;

} // 5. Simple Calculator using switch case #include using namespace std; int main() { double a, b; char op; cout << "Enter first number: "; cin >> a; cout << "Enter operator (+, -, *, /): "; cin >> op; cout << "Enter second number: "; cin >> b;

switch(op) {
    case '+': cout << "Result = " << a + b; break;
    case '-': cout << "Result = " << a - b; break;
    case '*': cout << "Result = " << a * b; break;
    case '/': 
        if(b != 0)
            cout << "Result = " << a / b;
        else
            cout << "Division by zero error!";
        break;
    default: cout << "Invalid operator!";
}
return 0;

} // 6. Print Prime Numbers in a Given Range #include using namespace std; int main() { int start, end; cout << "Enter range (start end): "; cin >> start >> end;

cout << "Prime numbers between " << start << " and " << end << " are: ";

for(int num = start; num <= end; num++) {
    bool isPrime = true;
    if(num < 2) continue;
    for(int i = 2; i*i <= num; i++) {
        if(num % i == 0) {
            isPrime = false;
            break;
        }
    }
    if(isPrime)
        cout << num << " ";
}
return 0;

}

// 7. Print Factors of a Number #include using namespace std; int main() { int n; cout << "Enter a number: "; cin >> n;

cout << "Factors of " << n << " are: ";
for(int i = 1; i <= n; i++) {
    if(n % i == 0)
        cout << i << " ";
}
return 0;

}

// 8. Find Roots of a Quadratic Equation #include #include using namespace std; int main() { double a, b, c, d, root1, root2; cout << "Enter coefficients a, b and c: "; cin >> a >> b >> c;

d = b*b - 4*a*c;

if(d > 0) {
    root1 = (-b + sqrt(d)) / (2*a);
    root2 = (-b - sqrt(d)) / (2*a);
    cout << "Roots are real and different.\n";
    cout << "Root 1 = " << root1 << ", Root 2 = " << root2;
}
else if(d == 0) {
    root1 = -b / (2*a);
    cout << "Roots are real and equal.\n";
    cout << "Root 1 = Root 2 = " << root1;
}
else {
    double realPart = -b / (2*a);
    double imagPart = sqrt(-d) / (2*a);
    cout << "Roots are complex and different.\n";
    cout << "Root 1 = " << realPart << " + " << imagPart << "i, ";
    cout << "Root 2 = " << realPart << " - " << imagPart << "i";
}
return 0;

}

// 9. Remove Duplicates from an Array #include using namespace std; int main() { int n; cout << "Enter number of elements: "; cin >> n;

int arr[100];
cout << "Enter array elements: ";
for(int i = 0; i < n; i++) {
    cin >> arr[i];
}

cout << "Array after removing duplicates: ";
for(int i = 0; i < n; i++) {
    bool duplicate = false;
    for(int j = 0; j < i; j++) {
        if(arr[i] == arr[j]) {
            duplicate = true;
            break;
        }
    }
    if(!duplicate)
        cout << arr[i] << " ";
}
return 0;

}