排序程序只顯示第一個和最後一個數

Question

我正在生成從-100到100的隨機數&我想按升序和降序對＃排序，但是當結果只顯示第一個&最後一個數字是顯示？

// sorting using function pointers. 
#include "stdafx.h" 
#include <fstream> // writing data to disk 
#include <cstdlib> // standard general utilities library "# generator" 
#include <ctime> // convert time value to string 
#include <iostream> 
#include <iomanip> // set precision 

using namespace std; 

// prototypes 
void selectionSort(int [], const int, bool (*)(int, int)); 
void swap(int * const, int * const); 
bool ascending(int, int); // implements ascending order 
bool descending(int, int); // implements descending order 

int _tmain(int argc, _TCHAR* argv[]) 
{ 

// Number Generator 
{ 
    double Final_Avg = 0; 
    double Random_Cap = 100; 
    double Samples_To_Create = 99; 
    srand((unsigned)time(0)); 
    double rndDbl; 
    int rndInt; 
    double rndAvg = 0, rndMin = 0, rndMax = 0; 
    int counter = 0; 
    double temp = 0; 
    double dblRanAry[100]; 

    Final_Avg = rndAvg/counter; // final average to display 

    double lDbl=0, hDbl=Random_Cap; 
    int lInt = 0, hInt=1; 

    double dblRange=(hDbl-lDbl)+1; 
    int intRange=(hInt-lInt)+1; 



    for(int index=0; index<Samples_To_Create; index++) 
    { 
    rndInt = lInt+int(intRange*rand()/(RAND_MAX + 1.0)); 
    rndDbl = lDbl+double(dblRange*rand()/(RAND_MAX + 1.0)); 

// random number if statement 
    if (rndInt == 0){ 
     rndDbl = -(rndDbl); 

    } //start of Min/Max if statements 
    if (rndMin == 0){ 
     rndMin = rndDbl; 
    } 
    else if (rndDbl < rndMin){ 
     rndMin = rndDbl; 
    } 
    if (rndMax == 0){ 
     rndMax = rndDbl; 
    } 
    else if (rndDbl > rndMax){ 
     rndMax = rndDbl; 
    } //end of Min Max if statements 

    temp = rndDbl; 
    rndAvg += temp; 
    dblRanAry[counter] = temp; 
    counter++; 

    } 

    const int arraySize = 100; 
    int order; // 1 = ascending, 2 = descending 
    int counter1; // array index 

// **我認爲這個問題是在這裏**

int a[ arraySize ] = { rndDbl }; 

    cout << "Enter 1 to sort in ascending order,\n" 
     << "Enter 2 to sort in descending order: "; 
    cin >> order; 
    cout << "\nData items in original order\n"; 

// output original array 
    for (counter1 = 0; counter1 < arraySize; ++counter1) 
     cout << setw(4) << a[ counter1 ]; 

// sort array in ascending order; pass function ascending 
// as an argument to specify ascending sorting order 
    if (order == 1) 
    { 
     selectionSort(a, arraySize, ascending); 
     cout << "\nData items in ascending order\n"; 
    } // end if 

    // sort array in descending order; pass function descending 
    // as an argument to specify descending sorting order 
    else 
    { 
     selectionSort(a, arraySize, descending); 
     cout << "\nData items in descending order\n"; 
    } // end else part of if...else 

    // output sorted array 
    for (counter1 = 0; counter1 < arraySize; ++counter1) 
     cout << setw(4) << a[ counter1 ]; 

    cout << endl; 
    system("pause"); 
} 
} // end main 

// multipurpose selection sort; the parameter compare is a pointer to 
// the comparison function that determines the sorting order 
void selectionSort(int work[], const int size, 
        bool (*compare)(int, int)) 
{ 
    int smallestOrLargest; // index of smallest (or largest) element 

    // loop over size - 1 elements 
    for (int i = 0; i < size - 1; ++i) 
    { 
     smallestOrLargest = i; // first index of remaining vector 

     // loop to find index of smallest (or largest) element 
     for (int index = i + 1; index < size; ++index) 
     if (!(*compare)(work[ smallestOrLargest ], work[ index ])) 
      smallestOrLargest = index; 

     swap(&work[ smallestOrLargest ], &work[ i ]); 
    } // end if 
} // end function selectionSort 

// swap values at memory locations to which 
// element1Ptr and element2Ptr point 
void swap(int * const element1Ptr, int * const element2Ptr) 
{ 
    int hold = *element1Ptr; 
    *element1Ptr = *element2Ptr; 
    *element2Ptr = hold; 
} // end function swap 

// determine whether element a is less than 
// element b for an ascending order sort 
bool ascending(int a, int b) 
{ 
    return a < b; // returns true if a is less than b 
} // end function ascending 

// determine whether element a is greater than 
// element b for a descending order sort 
bool descending(int a, int b) 
{ 
    return a > b; // returns true if a is greater than b 
} // end function descending 

Answer 1

是，這個問題，確實有。當你需要複製整個數組

int a[ arraySize ] = { rndDbl }; 

將初始化第一個元素a從double rndDbl;值。

int a[ arraySize ]; 
    for (counter1 = 0; counter1 < arraySize; ++counter1) 
    a[ counter1 ] = dblRanAry[counter1]; 

通過我沒有看到什麼是創建數組持有雙打，只有在它充滿數據後纔將它們轉換爲int。爲什麼不直接填寫a的數據。