Program : 13

PROGRAM - 13

a) 2’s compliment of a number is obtained by scanning it from right to left and the complementing all the bits after is 00100. Write a program to find the 2’s complement of a given binary number using functions.

Program:

#include<stdio.h>

#include<conio.h>

#include<string.h>

void main()

{

char str1[20];

int i,n,k;

clrscr();

puts("enter the string\n");

gets(str1);

n=strlen(str1);

for(i=n-1;i>=0;i--)

{

if(str1[i]=='1')

{

k=1;

break;

}

}

if(k==1)

{

for(i=i-1;i>=0;i--)

{

if(str1[i]=='1')

str1[i]='0';

else

str1[i]='1';

}

}

printf ("2's complement is:   ");

puts(str1);

getch();

}

 

b) Write a program to convert a roman number 

  in to its decimal equivalent using functions.

Program:

#include<stdio.h>

#include<conio.h>

#include<string.h>

void main()

{

char r[10];

void roman(char []);

clrscr();

printf("enter roman no.:");

scanf("%s",&r);

roman(r);

getch();

}

void roman(char rom[])

{

int i,k,len,a[20],count=0;

len=strlen(rom);

for(i=len-1;i>=0;i--)

{

  if(rom[i]=='I')

   {

     count++;

   }

  if((rom[i-1]=='I')&&(rom[len-1]>rom[i-1]))

   {

    count++;

   }

 }

 if(count>=4)

 {

   printf("invalild");

   getch();

   exit();

  }

else

{

for(i=0;i<len;i++)

{

if(rom[i]=='I')

a[i]=1;

else if(rom[i]=='V')

a[i]=5;

else if(rom[i]=='X')

a[i]=10;

else if(rom[i]=='L')

a[i]=50;

else if(rom[i]=='C')

a[i]=100;

else if(rom[i]=='D')

a[i]=500;

else if(rom[i]=='M')

a[i]=1000;

}

k=a[len-1];

for(i=len-1;i>0;i--)

{

if(a[i]>a[i-1])

k=k-a[i-1];

else if(a[i]==a[i-1]||a[i]<a[i-1])

k=k+a[i-1];

}

}

printf("decimal is:");

printf("%d",k);

}