Program/sqr.cpp at master · DongYuYu/Program · GitHub

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


double mean (float a[]){


       int sum =0, i;
       int b= sizeof(a);
       printf("%d\n",b);
       for (i=0; i<b; i++)
       {sum += a[i];
       //printf("%d\n",a[i]);

       }
       printf ("sum=%d\n", sum);
       double n = b;


       printf("av=%f\n",sum/n);
       return sum/n;


       }


double sigma (float a[]){
int b =sizeof(a);
int i;
double avg =  mean(a), sum=0;
for (i=0;i <b; i++)
sum += (a[i]-avg)*(a[i]-avg);

double n = b;

return sqrt(sum/n);


}

int main (){


 const int n=5;
 //int n;
 //while (scanf("%d", &n)!=EOF){
 float a[n];
 int i;
 for (i=0; i<n; i++){

     scanf("%d",&a[i]);

     //printf("%d\n", i);


     }


 printf("srtt= %f\n",sigma(a));


//}
 system("pause");

 return 0;


}