/* Project, Author, Date */   
  /* Size Of Factorial program */
  /* (This is obviously not a first C program) */

 #include <stdio.h>/* s removed, ; removed */ 
 #include <math.h> /* need for log10 */ 

  int main()
  { 
    int len; /* size of n!, to be found */ 
    int n;   /* given value */  
    int j; /* iteration index. Identifier `i' was not the one used in the loop. */
    double logNFac; /* accumulator for log10 (j!), j=0,...,n.  Note: log10 (0!)=0.*/ 
    /*Bring the declaration here. Declarations must precede executable statements*/ 

  printf("Given an n>=0, this program computes the size of n!\n");
  printf("Please enter n="); /* A prompt is needed before scanf */  
  scanf("%d", &n);
  if (n<0) /* n==0 is still OK */ 
  { /*braces made properly indented */
     printf("n<0, factorial undefined\n");
     return (0);   placed in its own line 
  }
  
  /*'else' removed, since previous 'if' ends with 'return(0)'*/

   /* In loop: log10 (n!) = sum log10(j), j=1,..,n. */
   logNFac=0.0; /* Initialization */
   for (j=1; j<=n; j++) /* no ; here */;
   { /* indent next line properly */ 
     logNFac+=log10((double)j);  /* using function log10 from "math.h" */
   } /* no ; here */
 
   /* Now that log10(n!) is computed, find its integral part */
   len=(int) logNFac; /* cast to int */

   /* if the value was rounded up, subtract one */
   if (len > logNFac)  /*  remove 'then' */
      --len;
   /* To obtain size of n!, add 1 to the computed integral part */
   len+=1;   /*  undefined varname `size' and invalid shorthand `=+' were here */ 
   /* Print result, like this: Size of 4 ! is 2 */ 
   printf("Size of %d ! is %d\n", n, len); 
   return(0);
 }