签到题，考察是否掌握基础数据类型。

#include <stdio.h>
#include <math.h>
int n;
double a[1010];
double avg, single;

int main()
{
    scanf("%d", &n);
    for (int i = 1; i <= n; ++i)
        scanf("%lf", &a[i]), avg += a[i];
    avg /= n;
    for (int i = 1; i <= n; ++i)
        single += (a[i] - avg) * (a[i] - avg);
    single /= n, single = sqrt(single);
    for (int i = 1; i <= n; ++i)
        printf("%.10f\n", (a[i] - avg) / single);
}