To solve this problem we need to know the steps to convert a decimal number to binary / Octal / Hexadecimal number.

As you all know that conversion from binary to any base follows a single rule. And the rule is:

" To convert a decimal to N_base_number_system we need to divide the decimal by N till we reach to ZERO. In this process we need to store all the reminders and print them in a reversed way "

Approach to code :

• Take the decimal number from the user

• make 3 function for binary, octal, Hexadecimal

• For each function we will need a string to store the reminders and print them reversely

• In case of hexadecimal we will need to use conditions to get A,B,C,D,E,F

• We will convert integer to character using s[n++]=(char)(a%8+(int)'0') this technique.

My approach:

#include<stdio.h>

void binary(int a){

int n=0;

char s[10000];

while(a>0){

s[n++]=(char)(a%2+(int)'0');

a=a/2;

}

printf("Binary >> ");

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

printf("%c",s[n]);

}

printf("\n");

}

void octal(int a){

int n=0;

char s[10000];

while(a>0){

s[n++]=(char)(a%8+(int)'0');

a=a/8;

}

printf("Octal >> ");

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

printf("%c",s[n]);

}

printf("\n");

}

void hexa(int a){

int n=0,k;

char s[10000];

while(a>0){

k=a%16;

if(k<10) s[n++]=(char)(k+(int)'0');

else if(k==10) s[n++]='A';

else if(k==11) s[n++]='B';

else if(k==12) s[n++]='C';

else if(k==13) s[n++]='D';

else if(k==14) s[n++]='E';

else if(k==15) s[n++]='F';

a=a/16;

}

printf("Hexadecimal >> ");

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

printf("%c",s[n]);

}

printf("\n");

}

int main()

{

int a,choice;

printf("Enter the decimal number :: ");

scanf("%d",&a);

binary(a);

octal(a);

hexa(a);

return 0;

}

Sample I/O

Enter the decimal number :: 2345

Binary >> 100100101001

Octal >> 4451

Hexadecimal >> 929