Chapter 6 : More Complex Repetitions.md

Chapter-6 More Complex Repetitions

[A]

 (a)  prints nothing.
 
 (b)  1 (infinite times).
 
 (c)  2

[B]

 (a)  the initialization expression.
       the testing expression.
       the increasing/decreasing expression.
  
 (b)  a for loop.
  
 (c)  At least once.
 
 (d)  Initialization, execution of body, testing.
 
 (e)  3.
 
 (f)  Continue;
 
 (g)  Infinite times.
 
 (h)  The program will produce the output x = 10 y = 10.
       The ; after the if (x != y) would NOT produce an error.

 (i)  All things that can be done using a for loop can also be done using a while loop.
       for(; ;) implements an infinite loop.

[C]

(a)

  #include<stdio.h>
  int main()
  {
    int i,j,flag;
    for(i=1;i<=300;i++)
     flag=1;
     for(j=2;j<=i/2;j++)
     {
     if(i%j==0)
     {
     flag=0;
     break;
     }
   }
   if(flag==1)
   printf("%d\n",i);
   }
   return 0;
   }

(b)

  #include<stdio.h>
  int main()
  {
   int i=1;
   while(i)
   {
   printf("%c",i);
   }
   return 0;
  }

(c)

#include<stdio.h>
int main()
{
 int i,j,fact;
 float sum=0,d;
 for(i=1;i<=7;i++)
 {
   fact=1;
   for(j=1;j<=i;j++)
   {
     fact=fact*j;
   }
   d=i/fact;
   sum=sum+d;
  }
  printf("Sum of first seven terms is = %d",sum);
  return 0;
 }

(d)

#include<stdio.h>

   int main()
   {
int i,j,k;
for(i=1;i<=3;i++)
{
	for(j=1;j<=3;j++)
	{
		for(k=1;k<=3;k++)
		{
			if(i==j || i==k || j==k)
				continue;
			printf("%d, ", i*100+j*10+k);
		}
	}
}
printf("are the all possible combinations of 1,2 and 3.");
return 0;
 }

(e)

#include<stdio.h>
#include<stdlib.h>
int main()
{	
int year=0,inv,alt;
while(alt>inv)
{
year++;
alt=120*year;
inv=(1000*year)-4000;
}
printf("The minimum year is %d",year);
}

(f)

  #include<stdio.h>
  int main()
  {
    int n,i,mul;
printf("Enter a number = ");
scanf("%d",&n);
for(i=1;i<=10;i++)
{
 mul=n*i;
 printf("%d * %d = %d\n",n,i,mul);
    } 
return 0;
}

(g)

   #include<stdio.h>
    int main()
    {
int y;
float x,i;
printf("           y         x      =       i");

for(y=1;y<=6;y++)
{
	for(x=5.5;x<=12.5;x+=0.5)
	{
		i=2+(y+(x*0.5));
		printf("\n           %d     %f   =   %f", y, x, i);
		
	}
}
return 0;
   }

(h)

        #include<stdio.h>
        #include<math.h> 
         int main()
      {
   float i,p,q,r,n,a,d;
 for(i=1;i<=10;i++)
{
	printf("\n\nEnter principal, rate, time (in year) and compound interest respectively : ");
	scanf("%f %f %f %f", &p,&r,&n,&q);
	
	d=pow((1+r/q),n*q);
	a=p*b;
	
	printf("\n%f is the amount.", d);
}
return 0;
   }

(i)

       #include<stdio.h>
   #include<math.h>
   int main()
   {
      int a,x,i,j,term;
      float sol,sum;
      printf("Enter the value of x = ");
      scanf("%d",&x);
      term=(x-1)/x;
     sum=term;
     int power=2;
     for(i=1;i<=6;i++)
    {
	sol=pow(term,a)/2;
	sum=sum+sol;
	a++;
    }
    printf("%f is the sum of the series.\n", sum);
       return 0;
       }

(j)

      #include<stdio.h>
     int main()
       {
    int i, j, k;
    for(i = 1; i <= 30; i++)
      {
	for (j = i; j <= 30; j++)
	{
		for (k = j; k <= 30; k++)
		{
			if (i*i + j*j == k*k || j*j + k*k == i*i || i*i + k*k == j*j)
				printf("\n%d %d and %d", i, j, k);
		}
	}
}
printf(" are all pythogorian triplets.\n");
return 0;
      }

(k)

  #include<stdio.h>
  int main()
     {
   int population = 100000;
   for(int i = 0; i < 10; i++)
{
	population = population - (population / 100) * 10;
	printf("Year %d : %d\n", 10-i, population );
}
return 0;
   }

(l)

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

int main()
{
int num, i, j, k, l;
for (num = 1; num < 5000; num++)
{
	for (i = 1; i < num; i++)
	{
		if (num < i*i*i)
			break;
	for (j = i + 1; j < num; j++)
		{
			if (num < j*j*j)
				break;
	for (k = i + 1; k < num; k++)
			{
				if (k*k*k > i*i*i + j*j*j)
				break;
		for (l = k + 1; l < num; l++)
				{
			if (num < k*k*k + l*l*l)
						break;
		if ((num == i*i*i + j*j*j) && (num == k*k*k + l*l*l))
	{
		printf("\n%d^3 + %d^3 = %d^3 + %d^3 = num : %d",i, j, k, l, num);
			break;
					}
				}
			}
		}
	}
}
getch();
return 0;
}

(m)

#include<stdio.h>
#include<conio.h>
int main()
{
int hr;
for(hr = 0; hr < 24; hr++)
{
	if(hr == 0)
		printf("\n12 Midnight");
	if(hr > 0 && hr < 12)
		printf("\n%d AM", hr);
	if(hr == 12)
		printf("\n%d Noon.", hr);
	if(hr > 12 && hr < 24)
		printf("\n%d PM.", hr-12);
}
getch();
return 0;
}

(n) Floyd's Triangle

#include<stdio.h>
int main()
{
 int num,r,c,sp,i=1;
 printf("Enter any number : ");
 scanf("%d", &num);
	 for(r=1; r<=num; r++)
{
 	 for(sp=1; sp<=num-r; sp++)
   printf(" ");
  for(c=1; c<=r; c++,i++)
printf("%d ",i);  
 printf("\n");
 }
return 0;
}

(o)

void main()
{
int i,j,k;
for(i=7;i>=1;i--)
{
for(j=1;j<=7;j++)
{
if(j<=i)
printf("%c",'A' + j-1);
else
printf(" ");
}
for(j=6;j>=1;j--)
{
if(j<=i)
printf("%c",'A' + j-1);
else
printf(" ");
} 
printf("\n");
	}
}	

(p)

Pascal’s triangle is a triangular array of the binomial coefficients.

#include <stdio.h>
int main()
{
int rows, coef = 1, space, i, j;

printf("Enter number of rows: ");
scanf("%d",&rows);

for(i=0; i<rows; i++)
{
    for(space=1; space <= rows-i; space++)
        printf("  ");

    for(j=0; j <= i; j++)
    {
        if (j==0 || i==0)
            coef = 1;
        else
            coef = coef*(i-j+1)/j;

        printf("%4d", coef);
    }
    printf("\n");
}

return 0;
}