597続き
#include<stdio.h>
#include<math.h>
int main()
{
int a[21],c[10001],s,n,i,b;
double av,sd,sd2;
for(n=1000;n<=10000;n=n+1000){
printf("n=%5d\n",n);
for (i=0;i<=21;i++);
a[i]=0;
s=0;
for (i=0;i<=n;i++){
b=random()%20+1;
c[i+1]=b;
a[b]++;
}
av=s/n;
for(i=1;i<=n;i++){
sd2(c[i] - av)*(c[i] - av)/n + sd2;
}
sd=sqrt(sd2);
printf("整数　出現回数\n");
for(i=1;i<=21;i++)
printf("%2d %d \n",i,a[i])

printf("平均値 %7.5f,標準偏差 %7.5\n",av,sd);
}
}