#include<math.h>
#include<stdio.h>
int main()
{
    double arr[1000];
    int i=0,count=0;
    while(scanf("%lf",&arr[i]))
    {
        arr[i] = sqrt(arr[i]);
        i++; count++;
    }
    for(i=count-1;i>=0;i--)
        printf("\n %0.4lf",arr[i]);
    return 0;
}

size of a = 1000 is not enought -> index was out of size
size of a maybe more than. Because file size = 256 KB. Unlimit A[i]. So that use array here is difficut to solve this problem!