#include <stdio.h>
#include <windows.h>
#include <math.h>
#define MAX 100


void input_array(int *a, int n);
int everage(int *a, int n);
int standard_deviation(int *a, int n);

void input_array(int *a, int n)
{
    int i;
    printf("\nn = ");
    scanf("%d",&n);
    for(i=0; i<n;i++){
        printf("a[%d] = ",i);
        scanf("%d",&a[i]);
    }
}

int everage(int *a, int n)
{
    int i,u,sum;
    sum=0;
    for(i=0; i<n; i++){
        sum+=a[i];
    }
    u = sum/n;
    return u;
}
int standard_deviation(int *a, int n)
{
    int i,o,sum;
    sum=0;
    for(i=0; i<n; i++){
        sum += pow( a[i]-everage(a,n), 2 );
    }
    o = sqrt(sum/n);
}

int main()
{
    int a[MAX], n;
    input_array(a,n);
    everage(a,n);
    printf("Ky vong cua day so: %d",everage(a,n));
    standard_deviation(a, n);
    printf("Do lech chuan cua day so: %d",standard_deviation(a, n));
    system("pause");
    return 0;
}