C++插入排序

Question

I have this function called WordSort(worddata W [], int count) that is fed two variables 1 - worddata is the array holding information on a given word in a file. count is just the counter variable to see which word in the array we are looking at.

the words.txt file that is read into this program would just be a string of words.

this is a list of words
there are letters and numbers
23 people recommend this program.

Heres the function:

void WordSort (worddata W [], int count)
{
  for (int i=1; i < count; i++)
         {
           for (int j=i; j > 0 && W[j-1].word > W[j].word; j--)
             {
               Swap(W[j], W[j-1]);
             }
         }
}

The swap function is suppose to swap every element with the one before it as long as j > 0 or the list is over. Im confused on how to complete the swap function, here's the example i was given.

void Swap (worddata & a, worddata & b)
{
 int += a;
 a = b;
 b =+;
}

Swap is suppose to swap every element with the one before it

I think the WordSort function works fine, the only thing missing is the Swap function. Could anyone point me in the right direction or explain insertion sorting better to me?

Answer 1

void insertion_sort()
{


    /* Algorithm : Insertion Sort
     * Coded by .
    */
    int num;
    /*
     * Asking the User no of Integers he/she wants to enter
     */
    cout << "Enter no of integers u want to enter: ";
    cin >> num;
    /* Creating an Array to store the integers*/
    int s[num];
    /*Taking Integers from the User */
    for(int i = 0 ; i < num ; i++)
    {
        cout << "Integer " << i+1 << " is : ";
        int x;
        cin >> x;
        s[i] = x;
    }
    /* The Magic of INSERTION SORT */
    for(int j = 1 ; j <= (num-1) ; j++)
    {
        int key = s[j]; 
        int k = j-1;

        while(k >=0 && key <= s[k])
        {
            s[k+1] = s[k];
            k = k - 1;
        }
        s[k+1]=key;

    }
    /*Printing Out the Sorted List */
    cout << "The Sorted List is \n\n";
    for(int i = 0 ; i < num ; i++)
    {
        cout << s[i] << "  ";
    }

}

Answer 2

Use standard library std::swap instead. In your loop:

for (...)
{
    std:swap(W[j], W[j-1]);
}

std::swap requires worddata class to have a copy constructor and an assignment operator defined explicitly or implicitly.

Answer 3

Swap should look like this -- I have no idea how your example is even close.

void Swap (worddata & a, worddata & b)
{
 worddata temp = a;
 a = b;
 b = temp;
}

Answer 4

Insertion sort using "for loop" (2 iterations)

#include<iostream>
using namespace std;


int insertion(int arr[], int size_arr)
{
    int i,j,n, temp;

    for(i=1;i<size_arr; i++){
            j=i-1;
            temp = arr[i];
            for (j; j >=  0; j--)
        {
            if(arr[j] > temp){
                        arr[j+1] = arr[j];
                        arr[j] = temp;
            }
        }
            arr[j] = temp;
      }

    for(i=0;i<size_arr;i++){
        cout<<arr[i]<<endl;
    }
    return 0;
}

int main(){
    int arr[] = {3,38,1,44,66,23,105,90,4,6};
    int size_arr = sizeof(arr) / sizeof(arr[0]);
    insertion(arr,size_arr);
    return 0;
}