1 #include <stdio.h>
  2 #include <stdlib.h>
  3 #include <math.h>
  4
  5 int main()
  6 {
  7     double m=pow(10,18);
  8
  9     long int arr[131072];
 10     int count=0,i;
 11
 12     long int d;
 13     while(scanf("%ld",&d)!=EOF)
 14     {
 15         arr[count++]=d;
 16     }
 17
 18     for(i=count-1;i>=0;i--)
 19     {
 20         double val=(double)arr[i];
 21         printf("%.4f\n",val>m?0:sqrt(val));
 22     }
 23
 24     return 0;
 25 }

I tried it with the input they gave for the example and it worked. Could someone point out what could be wrong with it?

why you checking for m ? I think better remove it

printf("%.4f\n" ... try \r\n instead of \n