总结程序的关键步骤(c++求均值，方差)

#include
#include
using namespace std;
void aveMsd( double [], int, double &, double & ); //求平均值和均方差值函数
int main()
{
double s[] = { 76, 85, 54, 77, 93, 83, 90, 67, 81, 65 };
double ave, msd;
int i, n;
n = sizeof( s )/sizeof( double ); //求数组元素的个数
cout<<"学生成绩：";
for( i=0; i<n; i++ )
cout<<s[i]<<" ";
cout<<endl;
aveMsd( s, n, ave, msd );
cout << "平均值：" << ave << endl << "均方差值：" << msd << endl;
}
void aveMsd( double s[], int n, double &ave, double &msd )
{
int i;
double sum1=0, sum2=0;
for( i=0; i<n; i++ ) //求平均值
sum1 += s[i];
ave = sum1/n;
for( i=0; i<n; i++ ) //求均方差
sum2 += pow( s[i]-ave, 2 );
msd = sqrt( sum2/n );
}