Control Flow And Decision Making Practice Problems

#include <stdio.h> Copy Code
int main () {
int number;

printf ("Enter an integer: ");
scanf ("%d", &number);

// Check if the number is even or odd
if ( number % 2 == 0) {
printf ("%d is an even number. ", number );
} else {
printf ("%d is an odd number. ", number );
}

return 0;
}

#include <stdio.h> Copy Code
int main () {
char character;

printf ("Enter a character: ");
scanf (" %c", &character); // Note the space before %c to consume the newline character

// Check if the character is an alphabet
if ((character >= 'a' && character <= 'z') || (character >= 'A' && character <= 'Z')) {
// Check if the character is a vowel
if (character == 'a' || character == 'e' || character == 'i' || character == 'o' || character == 'u' ||
character == 'A' || character == 'E' || character == 'I' || character == 'O' || character == 'U') {
printf ("%c is a vowel. ", character);
} else {
printf ("%c is a consonant. ", character);
}
} else {
printf ("Invalid input. Please enter an alphabet. ");
}

return 0;
}

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

int main () {
double a, b, c, discriminant, root1, root2;

printf ("Enter coefficients (a, b, c) of the quadratic equation (ax^2 + bx + c = 0): ");
scanf ("%lf %lf %lf", &a, &b, &c);

// Calculate discriminant
discriminant = b * b - 4 * a * c ;

// Check the nature of the roots
if ( discriminant > 0) {
// Two real and distinct roots
root1 = (- b + sqrt(discriminant)) / (2 * a) ;
root2 = (- b - sqrt(discriminant)) / (2 * a) ;
printf ("Roots are real and distinct: ");
printf ("Root 1: %lf ", root1 );
printf ("Root 2: %lf ", root2 );
} else if ( discriminant == 0) {
// Two real and equal roots
root1 = - b / (2 * a) ;
printf ("Roots are real and equal: ");
printf ("Root 1 = Root 2: %lf ", root1 );
} else {
// Complex roots
double realPart = - b / (2 * a) ;
double imaginaryPart = sqrt(-discriminant) / (2 * a) ;
printf ("Roots are complex and conjugate: ");
printf ("Root 1: %lf + %lfi ", realPart , imaginaryPart );
printf ("Root 2: %lf - %lfi ", realPart , imaginaryPart );
}

return 0;
}

#include <stdio.h> Copy Code
int main () {
int n, first = 0, second = 1, next;

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

printf ("Fibonacci Series: ");

for ( int i = 0; i < n; i++) {
if (i <= 1) {
next = i;
} else {
next = first + second;
first = second;
second = next;
}
printf ("%d ", next );
}

return 0;
}