/*

The standard library contains a function called atoi, which takes a string (presumably a string of digits) and converts it to an integer. For example, atoi(“345”) would return the integer 345. Write a program that reads lines (using getline), converts each line to an integer using atoi, and computes the average of all the numbers read. Also compute the standard deviation.

*/


#include<stdio.h>
#include<conio.h>
#include<stdlib.h> // for atoi(), malloc
#include<math.h> // for pow(), sqrt() 
void main()
{
char str[10];
int i,n,*p=NULL,s=0;
float avg,sd,x=0.0;

clrscr();
printf("How many integer(s): ");
scanf("%d",&n);

p=(int*)malloc(n*sizeof(int)); // Memory allocation

for(i=0;i<n;i++)
{
printf("No.%d: ",i+1);
fflush(stdin); // Flashes the standard input-stream buffer
gets(str);
*(p+i) = atoi(str);
s += *(p+i);
}
// Average or Mean calculation
avg = (float)s/n;

// Standard Deviation calculation
for(i=0;i<n;i++)
x += pow(*(p+i)-avg,2);
sd = sqrt(x/n);

printf("\n\nNumbers read:\n");
for(i=0;i<n;i++)
printf("%d ",*(p+i));

printf("\n\nAverage: %-13.2f",avg);
printf("\n\nStandrad Deviation: %-13.2f (aprox.)",sd);
}