#include<stdio.h>
int hexadecimal_decimal(char hex[100])
{
    int i = 0, val,decimal,len;
    decimal = 0;
    len = strlen(hex);
    len--;
    for(i=0; hex[i]!='\0'; i++)
    {
        if(hex[i]>='0' && hex[i]<='9')
        {
            val = hex[i] - 48;
        }
        else if(hex[i]>='a' && hex[i]<='f')
        {
            val = hex[i] - 97 + 10;
        }
        else if(hex[i]>='A' && hex[i]<='F')
        {
            val = hex[i] - 65 + 10;
        }

        decimal += val * pow(16, len);
        len--;

    }
    return decimal;

}
int  octaldecimal(int c)
{
    int temp=0,i=0,mod;
    while(c!=0)
    {
        mod=c%10;
        temp=temp+mod*pow(8,i);
        c=c/10;
        i++;
    }
    return temp;
}
int  decimal(int c)
{
    int temp=0,i=0,mod;
    while(c!=0)
    {
        mod=c%10;
        temp=temp+mod*pow(2,i);
        c=c/10;
        i++;
    }
    return temp;
}
void hexadecimal(int a)
{
    int  i=0,count=0,arr[1000];
    while(a!=0)
    {
        arr[i]=a%16;
        count+=1;
        a=a/16;
        if(arr[i]<10)
        {
            arr[i]=48+arr[i];
        }
        else if(arr[i]>=10)
        {
            arr[i]=55+arr[i];
        }
        i++;

    }
    for(i=count-1; i>=0; i--)
    {
        printf("%c",arr[i]);
    }
}
void dci_oct(int c)
{
    printf("%o",c);
}
void binary(int c)
{
    int count=0,i=0,arr[1000];
    while(c!=0)
    {
        arr[i]=c%2;
        count+=1;
        c=c/2;
        i++;
    }
    for(i=count-1; i>=0; i--)
    {
        printf("%d",arr[i]);
    }
}
int main()
{
    char str[50];
    int a,c,x,i;
    printf("Select operator \n");
    printf("1. DIC\n");
    printf("2. BIN\n");
    printf("3. OCT\n");
    printf("4. HEX\n");
    for(i=0; ; i++)
    {
        scanf("%d",&a);
        if(a==1)
        {
            printf("DIC ");
            scanf("%d",&c);
            printf("BIN ");
            binary(c);
            printf("\nOCT ");
            dci_oct(c);
            printf("\nHEX ");
            hexadecimal(c);
        }
        else if(a==2)
        {
            printf("BIN ");
            scanf("%d",&c);
            x=decimal(c);
            printf("DIC %d\n",x);
            printf("OCT %o\n",x);
            printf("HEX ");
            hexadecimal(x);
        }
        else if(a==3)
        {
            printf("OCT ");
            scanf("%d",&c);
            printf("BIN ");
            x=octaldecimal(c);
            binary(x);
            printf("\nDIC %d\n",x);
            printf("HIX ");
            hexadecimal(x);

        }
        else if(a==4)
        {
            printf("HEX ");
            scanf("%s",str);
            x=hexadecimal_decimal(str);
            printf("DIC %d\n",x);
            printf("BIN ");
            binary(x);
            printf("\nOCT ");
            dci_oct(x);

        }
        else
       {
           printf("Wrong operator");
           break;
       }
    }
}