2 3

mian.cpp 

#include<iostream>
using namespace std;
int score[50];
void input_score(int s[],int m);    //自定义函数，将同学成绩输入
int get_max_score(int s[],int m);   //自定义函数，求最大值
int get_min_score(int s[],int m);   //自定义函数，求最小值
double get_avg_score(int s[],int m);   //自定义函数，求平均值
int countt(int x,int s[],int m ) ;       //自定义函数，计算得X分的有N同学
void output_index(int x,int s[],int m);  //自定义函数，输出得X分的同学的学号
double get_stdew_score(int x, int s[],int m);  //自定义函数，求标准差

int main()
{
    int score[50];
    int num;
    int iMin;
    int iMax;
    double iAverage;
    cout<<"小组共有几位同学";
    cin>>num;
    input_score(score,num);
    cout<<endl;
    cout<<"最高成绩为 ";
    iMax=get_max_score(score,num);
    cout<<iMax<<endl;
    cout<<"最低成绩为 ";
    iMin=get_min_score(score,num);
    cout<<iMin<<endl;
    cout<<"平均成绩为";
    iAverage=get_avg_score(score,num);
    cout<<iAverage<<endl;
    cout<<"取得最高成绩"<<iMax<<"分的有"<<countt(iMax,score,num)<<"人"<<"学号为";
    output_index(iMax,score,num);
    cout<<endl;
    cout<<"取得最低成绩"<<iMin<<"分的有"<<countt(iMin,score,num)<<"人"<<"学号为";
    output_index(iMin,score,num);
    cout<<endl;
    cout<<"标准偏差为"<< get_stdew_score(iAverage,score,num)<<endl;
return 0;
}

2.0.cpp

#include<iostream>
using namespace std;
void input_score(int s[],int m)
{    int i=1;
    int iScore;
    int n=0;
    cout<<"输入同学的成绩"<<endl;
    while(i<=m)
    {
        cout<<" 输入第"<<i<<"位同学的成绩";

        cin>>iScore;
        if(iScore>=0&&iScore<=100)
        {
            s[n++]=iScore;
            ++i;

        }
        else
        {
            cout<<"输入错误，请重新输入"<<endl;
        }
    }
}


2.1.cpp

int get_max_score(int s[],int m)
{
    int p=0;
    int iMax;
    iMax=s[p];
    p=1;
    for(;p<=m-1;++p)
    {
        if(s[p]>iMax)
            iMax=s[p];
    }
    return iMax;

}


2.2.cpp

int get_min_score(int s[],int m)
{
    int p=0;
    int iMin;
    iMin=s[p];
    p=1;
    for(;p<=m-1;++p)
    {
        if(s[p]<iMin)
            iMin=s[p];
    }
    return iMin;

}


2.3.cpp

double get_avg_score(int s[],int m)
{
    double iAverage;
    double iSum=0;
    int p=0;
    int n;
    n=m; 
    for(;p<=m-1;++p)
    {
        iSum+=s[p];
    }
    iAverage=(iSum/n);
    return iAverage;
}


2.4.cpp


int countt(int x,int s[],int m)
{
    int n=0;
    int p=0;
    for (;p<=m-1;++p)
    {
    if(s[p]==x)
    {
        ++n;
    }
    }
    return n;
}



2.5.cpp


#include<iostream>
using namespace std;
void output_index(int x,int s[],int m)
{
    int p=0;
    for(;p<=m-1;++p)
    {
        if(s[p]==x)
        {
            cout<<p+1<<" ";
        }
    }
}


2.6.cpp


#include<cmath>
double get_stdew_score( int x,int s[],int m)
{
    double dSum;
    double a,b;
    int p;
    p=0;
    double n;
    n=m;
    for(;p<=m-1;++p)
    {
       b=sqrt(s[p]-x);
       dSum=b*b;
    }
    a=(dSum/n);
    a=sqrt(a);
    return a;
}

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