c++ - 搜索逻辑错误

Question

我最近完成了我的代码，但是我的 bubbleSort 函数的输出是错误的。我错过了前两个要素。

我试着改变了一下，但还是没有成功。

NUM_FOR_CAL1

NUM_FOR_CAL2

看来是我的问题。

有人知道如何解决这个逻辑错误吗？

 //Searching Benchmarks exercise
#include <iostream>
#include <stdlib.h>

using namespace std;

//module prototypes
int binarySearch(int t, int arr[], int n);
int bubbleSort(int num[], int n);
void printArray(int arr[], int SIZE);


//global constants
const int SIZE=20;
const int NUM_FOR_CAL1=1;
const int NUM_FOR_CAL2=2;
const int ZERO_FOR_CAL=0;

int main()
{
    //some variables
   int swap;
   int arr[SIZE] = {26, 45, 56, 12, 78, 74, 39, 22, 5, 90, 87, 32, 28, 11, 93, 62, 79, 53, 22, 51};

   //Showing original order, bubble sort, and the number of swaps
   cout << "Original Order : ";
   printArray(arr, SIZE);
   swap = bubbleSort(arr, SIZE);
   cout << "Bubble Sorted : ";
   printArray(arr, SIZE);
   cout << "Number of location swaps: " << swap << endl;
   int num, pos, total = ZERO_FOR_CAL;
   char YesNo;
   do
   {
      cout << "Select a number in the Array to search for: ";
      cin >> num;
      pos = binarySearch(num, arr, SIZE);
      cout << "Sequential Search comparisons: " << pos + NUM_FOR_CAL1<< endl;
      cout << "The position of the number is " << pos + NUM_FOR_CAL1 << endl;
      if(pos != -NUM_FOR_CAL1) total++;
      cout << "Binary Search comparisons: " << total << endl;
      cout << "The position of the number is " << pos + NUM_FOR_CAL1 << endl;
      cout << "Do you want to search again (Y = Yes) : ";
      YesNo = NUM_FOR_CAL2;
      cin >> YesNo;
   }//end of do while loop to search for array and display comparisons
    while(YesNo == 'Y' || YesNo == 'y');

   system("Pause");
   return 0;
}//end main

//searching array using binarySearch
int binarySearch(int t, int arr[], int n)

{
   for(int i = ZERO_FOR_CAL; i < n; ++i)
     if(arr[i] == t) return i;
   return -NUM_FOR_CAL1;
}//end of binarySearch

//searching array using bubbleSort
int bubbleSort(int num[], int n)
{
int i, j, flag = NUM_FOR_CAL1;
int temp, swap = ZERO_FOR_CAL;

for(i = NUM_FOR_CAL1; (i <= n) && flag; i++)
{
    flag = NUM_FOR_CAL2;
    for (j = NUM_FOR_CAL2; j < (n-NUM_FOR_CAL1); j++)
    {
        if (num[j+NUM_FOR_CAL1] < num[j])
        {
            temp = num[j];
            num[j] = num[j+NUM_FOR_CAL1];
            num[j+NUM_FOR_CAL1] = temp;
            flag = NUM_FOR_CAL1;
            swap++;
        }//end of if statement
    }//end of for loop
}//end of for loop
return swap;
}//end bubbleSort

void printArray(int arr[], int SIZE)
{

   for(int i = 0; i < SIZE; i++)
   {
      cout << arr[i];
      if(i < SIZE - 1) cout << ", ";
   }
   cout << endl;
}

Answer 1

你的 j 循环:

for (j = NUM_FOR_CAL2; ... )

从 j=2 开始，所以它根本不会查看数组的前两个元素。

检测此问题的一个好方法是从较小的数组开始并使用如下诊断输出语句:

cout << "now comparing " << num[j+1] << " to " << num[j] << endl;