BasicsOfComputerSoftwareEngineering/POP/07/Optional01.c

#include <stdio.h>
#include <math.h>

int main() {
    int i = 1;
    double count = 0;
    for (; i < 1001; i++) {
        count += log10(i);
    }
    printf("1000! has %d digits.", ((int)count) + 1);
    return 0;
}