#include <stdio.h>
#include <math.h>
// double log10(double x);
int main(int argc, char **argv)
{
printf("%.2f\n", log10(123));
printf("%d\n", (int)log10(123));
printf("%.2f\n", log10(1234));
printf("%d\n", (int)log10(1234));
printf("%.2f\n", log10(12345));
printf("%d\n", (int)log10(12345));
return(0);
}
/*
run:
2.09
2
3.09
3
4.09
4
*/