gistfile1.hpp

#include <iostream>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <cstring>
#define RANDOMIZE srand((unsigned)time(NULL))
// Integrated Development Environment
// Visual C++
using namespace std;
//
struct students{
        double scores[50];
        double average;
        double stdev;
        double Me, Q1, Q3;
};
typedef struct students SStudent;
typedef struct ARR
{
        double* p;
        size_t length;
}SArr;
// C++ 同名 sort 函式
void sort(double scores[], int len);
void sort(SArr& arr);
double computeAverage(struct students X);
void OtherComputing(SStudent& s);
void Print(SStudent& s);
//
void main(int argc, char** argv)
{
        RANDOMIZE;
        SStudent s;
        // Windows.h ZeroMemory 巨集
        memset( (void*) &s, 0, sizeof(SStudent));
        size_t len = sizeof(s.scores) / sizeof(s.scores[0]);
        for (size_t i = 0; i < len; i ++)
        {
                s.scores[i] = rand()%len;
        }
        OtherComputing(s);
        Print(s);
        system("PAUSE");
}
void sort(double score[], int len)
{
        SArr arr;
        arr.p = score;
        arr.length = len;
        sort(arr);
}
void sort(SArr& arr)
{
        for (size_t i = 0; i < arr.length; i ++)
        {
                for (size_t j = 0; j < arr.length; j ++)
                {
                        if ( arr.p[i] < arr.p[j] )
                        {
                                double a = arr.p[i];
                                arr.p[i] = arr.p[j];
                                arr.p[j] = a;
                        }
                }
        }
}
double computeAverage(struct students X)
{
        X.average = 0;
        size_t len = sizeof(X.scores) / sizeof(X.scores[0]);
        for (size_t i = 0; i < len; i ++)
        {
                X.average += X.scores[i];
        }
        X.average /= len;
        return X.average;
}
void OtherComputing(SStudent& s)
{
        // 平均數
        s.average = computeAverage(s);
        s.stdev = 0;
        SArr arr;
        arr.p = s.scores;
        arr.length = sizeof(s.scores) / sizeof(s.scores[0]);
        for (size_t i = 0; i < arr.length; i ++)
        {
                double a = s.average - arr.p[i];
                a *= a;
                s.stdev += a;
        }
        s.stdev /= arr.length;
        s.stdev = sqrt(s.stdev);
        sort(arr);
        // 奇數長度
        if ( (arr.length % 2) == 1 )
        {
                // 中位數
                s.Me = arr.p[arr.length / 2];
        }
        // 偶數長度
        else
        {
                // 中位數
                s.Me = arr.p[arr.length / 2];
                s.Me += arr.p[arr.length / 2 - 1];
                s.Me /= 2;
        }
        // 四分位數
        double pos = arr.length;
        pos /= 4;
        bool bMod = (arr.length % 4) != 0;
        if ( bMod )
        {
                size_t f = (size_t)pos;
                s.Q1 = arr.p[f];
                f = (size_t)(pos * 3);
                s.Q3 = arr.p[f];
        }
        else
        {
                size_t f = (size_t)pos;
                s.Q1 = arr.p[f - 1] + arr.p[f];
                f = (size_t)(pos * 3);
                s.Q3 = arr.p[f - 1] + arr.p[f];
        }
}
void Print(SStudent& s)
{
        size_t len = sizeof(s.scores) / sizeof(s.scores[0]);
        for (size_t i = 0; i < len; i ++)
        {
                cout<<" "<<s.scores[i];
        }
        cout<<endl;
        cout<<"Average = "<<s.average<<endl;
        cout<<"Median = "<<s.Me<<endl;
        cout<<"Q1 = "<<s.Q1<<endl;
        cout<<"Q3 = "<<s.Q3<<endl;
        cout<<"Standard deviation = "<<s.stdev<<endl;
}