#include <stdio.h>
#include <math.h>

#define NUM (3)

double getmin(double *arr, int n);
void getavsd(double *arr, int n, double *av, double *sd);

int main(void)
{
    double arr[NUM], av, sd;
    int i;
    
    for (i = 0; i < NUM; i++) {
        printf("%d番目の数を入力 > ", i + 1);
        scanf("%lf", &arr[i]);
    }
    
    printf("最 小 値=%f\n", getmin(arr, NUM));
    getavsd(arr, NUM, &av, &sd);
    printf("平 均 値=%f\n", av);
    printf("標準偏差=%f\n", sd);
    return 0;
}

double getmin(double *arr, int n)
{
    double min;
    int i;
    
    for (min = arr[0], i = 1; i < n; i++)
        if (arr[i] < min)
            min = arr[i];
    return min;
}

void getavsd(double *arr, int n, double *av, double *sd)
{
    double sum, sumsq;
    int i;
    
    for (sum = sumsq = i = 0; i < n; i++) {
        sum += arr[i];
        sumsq += arr[i] * arr[i];
    }
    *av = sum / n;
    *sd = sqrt(sumsq / n - *av * *av);
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <math.h>

#define BUF 10

typedef struct S_Set{
    int *item;
    int count;
    int sum;
    int min;
    void (*setitem)(struct S_Set *set, int i);
    double (*getave)(struct S_Set *set);
    double (*getsd)(struct S_Set *set);
}Set;

void set_item(Set *set, int i);
double get_ave(Set *set);
double get_sd(Set *set);

Set newSet(Set *set){
    static Set newset = {NULL, 0, 0, INT_MAX, set_item, get_ave, get_sd};
    memcpy(set, &newset, sizeof(Set));
    return *set;
}

int main(void){
    Set set = newSet(&set);
    int i, n;
    printf("x,y,z=");
    for(i = 0; i < 3; i++){
        scanf("%d", &n);
        set.setitem(&set, n);
    }
    printf("Min=%d\n", set.min);
    printf("Av.=%f\n", set.getave(&set));
    printf("Sd.=%f\n", set.getsd(&set));
    return 0;
}

void set_item(Set *set, int i){
    void *vp;
    if(set->count % BUF == 0){
        vp = realloc(set->item, sizeof(int) * (set->count + BUF));
        if(vp) set->item = vp;
        else exit(1);
    }
    set->item[set->count] = i;
    set->count++;
    set->sum += i;
    if(set->min > i) set->min = i;
}

double 
get_ave(Set *set){
    return (double)set->sum / set->count;
}

double get_sd(Set *set){
    int i, c = set->count,  d, d2 = 0;
    double a = set->getave(set);
    for(i = 0; i < c; i++){
        d = set->item[i] - a;
        d2 += d * d;
    }
    return sqrt(d2 / set->count);
}