Chapter 8 : Functions.md

Chapter-8 Functions

[A]

 (a)  Learn C
       Followed by C++, C# and Java
       (infinite times)
 
 (b)  100
 
 (c)  3.140000
 
 (d)  Error.

[B]

 (a)  Semicolor missing in the declaration of a function.
       A function cannot return more than one values.
 
 (b)  message function has return type void, so it cannot be assigned to any variable.
 
 (c)  Function definition argument should have a datatype.
       Function is not defined before calling, or there should be prototype declaration of the function.
 
 (d)  Invalid use of a semicolon.
 
 (e)  Function definition is invalid in other functions.
 
 (f)  void is send in the message as argument, which is invalid.

[C]

 (a)  No! There is an Invalid use of a semicolon.
 
 (b)
    (1)  False.
    (2)  False.
    (3)  True.
    (4)  False.
    (5)  True.
    (6)  True.
    (7)  True.
    (8)  False.
    (9)  True.
   (10)  False.

[D]

(a)

    #include<stdio.h>
    int fact(int );
    int main()
    {
     int num,fac;
     scanf("%d",&num);
     fac=fact(num);
     printf("%d",fac);
     return 0;
     }
     int fact(int n)
     {
       int i,factorial=1;
       for(i=1;i<=n;i++)
       {
         factorial*=i;
       }
       return factorial;
     }

(b)

   #include<stdio.h>
   #include<math.h>
   int power(int,int);
   int main()
   {
     int a,b,ans;
     scanf("%d %d",&a,&b);
     ans=power(a,b);
     printf("%d",ans);
    return 0;
   }
   int power(int a,int b)
   {
     int d;
     d=pow(a,b);
     return d;
   }

OR

#include<stdio.h>
   #include<math.h>
   int power(int,int);
   int main()
   {
     int a,b,ans;
     scanf("%d %d",&a,&b);
     ans=power(a,b);
     printf("%d",ans);
    return 0;
   }

int power(int x, int y)
{
int num = 1, i;
for (i = 1; i <= y; i++)
	num = num*x;
return(num);
}

(c)

    #include<stdio.h>
#include<conio.h>

void rom(int);
void print(int, char);

int main()
{
int yer;

printf("Enter the year : ");
scanf("%d", &yer);
printf("\nRoman equivalent of %d is : ", yer);
rom(yer);

getch();
return 0;
}

void rom(int yer)
{
int v, x, l, c, d, m;

m = yer / 1000;
print(m, 'm');
yer %= 1000;

d = yer / 500;
print(d, 'd');
yer %= 500;

c = yer / 100;
print(c, 'c');
yer %= 100;

l = yer / 50;
print(l, 'l');
yer %= 50;

x = yer / 10;
print(x, 'x');
yer %= 10;

v = yer / 5;
print(v, 'v');
yer %= 5;

print(yer, 'i');
}

void print(int a, char c)
{
int i;
for (i = 0; i < a; i++)
	printf("%c", c);
}

(d)

     #include<stdio.h>
     int calc(int );
     int main()
     {
       int year,leap;
       printf("Enter year = ");
       scanf("%d",&year);
       leap=calc(year);
       if(leap==1)
       printf("%d is leap year",year);
       else
       printf("%d is not a leap year",year);
       return 0;
     }
     int calc(int year)
     {
       if(yr % 4 == 0 && (yr % 100 != 0 || yr % 400 == 0))
       return 1;
       else
       return 0;
     } 

(e)

    #include<stdio.h>
    void prime(int );
    int main()
    {
      int num;
      printf("Enter a number = ");
      scanf("%d",&num);
      prime(num);
      return(0);
    }
    void prime(int n)
    {
      int i,j,isPrime=1;
      for(i=2;i<=n;i++)
      {
        if(n%i==0)
        {  
          isPrime=1; 
         for(j=2;j<=i/2;j++)
          {
           if(i%j==0)
           {
             isPrime=0;
             break;
           }
          }
          if(isPrime==1)
          printf("%d\n",i);
         }
       } 
       return 0;
     }

OR

#include<stdio.h>
#include<conio.h>
int check_prime(int);
void pf(int);
int main()
{
int num;
printf("Enter a number : ");
scanf("%d", &num);
pf(num);
_getch();
return 0;
}
void pf(int num)
{
int i;
for (i = 2; num != 1; i++) //loop for obtaining the numbers.
{
	if (num%i != 0)// If the number is not a factor
		continue;
	else
	{
    	//If the number is prime, so check if it is prime
		if(check_prime(i) == 1)
		{
			while (num%i == 0)
			{
				printf("%d, ", i);
				num /= i;
			}
		}
	}
}
}

//returns 1 if prime, otherwise 0.
int check_prime(int num)
{
int i = 2;
while(i < num)
{
	if(i%num == 0)
		return 0;
	i++;
}
if(i == num)
	return 1;
}