#include<stdio.h>

#include<conio.h>

#include<string.h>

#include<stdlib.h>

int tongchuso(long n)//nhu de so 1

{

int s=0, du;

while(n>0)

{

du=n%10;

s=s+du;

n=n/10;

}

return s;

}

void coso16(long n)

{

char s[100];

int i=0,du;

while(n>0)

{

du=n%16;

if(du<10)//neu so du nho hon 10 s[i]=so du

s[i]=du+'0';

else

s[i]=(du-10)+'A';//neu so du>=10 s[i]='A" + du-10

n=n/16;

i++;

}

s[i]='\0';

strrev(s);//lat nguoc sau ki tu S

puts(s);//in sua ra man hinh

}

void main()

{

long n;

printf("

nhap n=");scanf("%ld",&n);

printf("tong cac chu so la %d",tongchuso(n));

printf("

chuyen sang co so 16 la:

");

coso16(n);

getch();

}