The Natural Numbers are written successively as shown below:
12345678910111213141516..........., such that the 4th digit is '4' the 9th digit is '9' but the 11th digit is '0', the 15th digit '2', the 17th '3', and so on.
What is the 40,000th digit that appears in this list ?

(In reply to re: Agreed by SilverKnight)

Caveat: I don't know how to make this
text box preserve spaces, so the indentation is shot. Also, I know itoa would probably be faster than sprintf, but I'm lazy -- what's a microsecond or two anyway...

#include <stdio.h>
#include <stdlib.h>
#define TARGET 40000
main()
{
char s[50000], *cp, ss[10];
int i,j,len;
cp = s;
s[0]=0;
len=0;
for(i=1; len < TARGET+2 ; i++) {
sprintf(ss,"%d",i);
j=strlen(ss);
strcpy(cp,ss);
cp += j;
len += j;
}
printf("character %d = %c\n",TARGET,s[TARGET-1]);
}

Posted by Brian Wainscott on 2003-08-29 14:55:54