How to find the largest digit in a given number in most efficient way?

Question

Input: 23678210
Output: 8

Answer 1

int main()
{
    int i = 349678;
    int j =0,k;
    while(i){
        if (j < (k=(i %10))) {
            j = k;
        }
        i /=10;
    }
    printf("largest  digit is :%d\n",j);
}