c++ - Shell排序和排序验证

Question

我对编码相当陌生，我一直在努力研究这段代码，它允许我随机生成大量整数数组，选择特定的 shell 排序，然后测试数组是否排序正确。

#include <iostream>
#include <stdlib.h>
#include <time.h>
#define LISTLEN 100000
using namespace std;

void shellSort(int[], int, int[], int);
void testIfSorted(int[], int);

void main()
{
   {
    int list[LISTLEN];
    int seq1[] = {LISTLEN/2};
    int seq2[] = {2-1};
    int seq3[] = { 4 + 3 * (2 ^ 0) + 1 };
    int choice;

    for (int i = 1; i < LISTLEN; i++)
    {
        list[i] = rand() % LISTLEN + 1;

        cout << list[i] << endl;
    }
    cout << "\nEnter the Number for Which Sequence-Type You Wish to Use: \n"
        "1) Shell Sequence\n"
        "2) Hibbard Sequence\n"
        "3) Sedgewick Sequence\n";
        cin >> choice;

        if (choice == 1)
        {
            shellSort(list, LISTLEN, seq1, LISTLEN / 2);
        }
        else if (choice == 2)
        {
            shellSort(list, LISTLEN, seq2, (2 - 1));
        }
        else if (choice == 3)
        {
            shellSort(list, LISTLEN, seq3, (4 + 3 * (2 ^ 0) + 1));
        }

        cout << "\nVerifying List was Sorted\n";
            testIfSorted;
    }
}

    void shellSort(int arr[], int arrsize, int seq[], int seqsize)
    {
        clock_t t;
        t = clock();
        {
            int j, temp;
            for (int i = seqsize; i < arrsize; i += 1)
            {
                temp = seq[i];
                for (j = i; j >= seqsize && seq[j - seqsize] > temp; j -= seqsize)
                {
                    seq[j] = seq[j - seqsize];
                }
                seq[j] = temp;
                cout << temp << endl << endl;
            }
            t = clock() - t; 
            printf("It took me %d clicks (%f seconds).\n", t, ((float)t) / CLOCKS_PER_SEC);
        }
    }

    void testIfSorted(int list[], int length)
    {
        for (int i = 0; i < length - 1; i++)
        {
            if (list[i] < list[i + 1])
            {
                cout << "List Isn't Sorted Correctly\n";
            }
            else (list[i] > list[i + 1]);
            {
                cout << "List Sorted Correctly\n";
            }
        }
    }

我不知道我做错了什么，shell 排序实际上并没有对数组进行排序，或者至少它没有进行降序排序，如果程序确实检查以确保数组已排序正确地，它不会显示我希望它显示的消息。

Answer 1

我没有具体的答案，但这些是一些快速调试技巧:

1 - 通过 clang-format 运行代码。如果您没有/不能在您的计算机上安装它，可以使用在线格式化程序，例如 http://format.krzaq.cc/

2 - 使用 clang 编译器编译您的代码，并打开所有警告。同样，如果您没有/不能在您的计算机上安装 clang，则可以使用一些在线沙箱。为什么是 clang ？他们付出了巨大的努力来提供非常好的警告/错误消息。

我都做了，这就是 clang 对程序的评价(链接 here)

prog.cc:10:1: error: 'main' must return 'int'
void main()
^~~~
int

prog.cc:41:9: warning: expression result unused [-Wunused-value]
        testIfSorted;
        ^~~~~~~~~~~~

prog.cc:61:56: warning: format specifies type 'int' but the argument has type 'clock_t' (aka 'long') [-Wformat]
        printf("It took me %d clicks (%f seconds).\n", t, ((float)t) / CLOCKS_PER_SEC);
                           ~~                          ^
                           %ld

prog.cc:45:20: warning: unused parameter 'arr' [-Wunused-parameter]
void shellSort(int arr[], int arrsize, int seq[], int seqsize)
                   ^

prog.cc:72:22: warning: expression result unused [-Wunused-value]
            (list[i] > list[i + 1]);
             ~~~~~~~ ^ ~~~~~~~~~~~

4 warnings and 1 error generated.

这些可能会有帮助 - 特别是最后一个!