2^15 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.
What is the sum of the digits of the number 2^1000?
#include <stdio.h>
int main()
{
char st[500] = {0};
int sum = 0;
int i,j,k;
st[0]=2;
j = 0;
for(i=1;i<1000;i++)
{
for(k=0;k<j+1;k++)
{
st[k]<<=1; //每一位 x 2
}
for(k=0;k<j+1;k++) //進(jìn)位
{
st[k+1]+=st[k]/10;
st[k] = st[k]%10;
}
if(st[j+1]) j++; //有進(jìn)位，再加一位
}
for(j;j>=0;j--)
{
sum+=st[j];
}
printf("%d",sum);
return 0;
}
