从高到低排序输出

Question

I made a simple program that would just show the input as the output. My main problem is that I want to sort the output from high to low. Instead of being sorted from high to low, the output is just the same order as the input. Can someone check my codes and see why it is not sorting.

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#define size 7
#include<stdlib.h>
struct books
{
    int profit;
};
void load(struct books b[], int n)
{
    int i;
    for (i = 0; i < n; i++)
    {
        printf("Enter profit:\n");
        scanf("%d", &b[i].profit );
    }
}
void print(struct books b[], int n)
{
    int i;
    for (i = 0; i<n; i++)
    {
        printf("Profit is:%d\n",b[i].profit);
    }
}
void sort(struct books b[], int n)
{
    int i; int j;
    books t;
    for (i = 0; i < n-1; i++)
        for (j = 0; j < n-1 ; j++)
            if (b[j].profit < b[j + 1].profit)
            {
                t = b[j];
                b[j] = b[j + 1];
                b[j+1] = t;
            }
}
void main()
{
    books b[size];
    load(b, size);
    print(b, size);
    sort(b, size);
    system("pause");
}

Answer 1

If you want to print the sorted list, you need to call sort before calling print:

void main()
{
    books b[size];
    load(b, size);

    sort(b, size);
    print(b, size);

    system("pause");
}

Also, I think you need to define the books struct as

    struct books b[size];

if you want to avoid compiler errors.

Finally, to print the list from low to high rather than high to low you can either modify the sorting algorithm as suggested in the another answer, or you can modify the printing algorithm as below:

void print(struct books b[], int n)
{
    int i;
    for (i = n-1; i>0; i--)
    {
        printf("Profit is:%d\n",b[i].profit);
    }
}

Answer 2

Use something like this(inverted bubble sort):

void inverted_sort(books b[], int size){
    int profit;
    bool swap;

    do{
        swap = false;
        for (int i= 0; i < (size - 1); i++){
            if (b[i].profit < b[i + 1].profit){
                profit = b[i].profit;
                b[i].profit = b[i + 1].profit;
                b[i + 1].profit = profit;
                swap = true;
            }
        }

    } while (swap);
}

And remember to change the functions order, inverted_sort() must go before print() .

void main()
{
    books b[size];
    load(b, size);
    inverted_sort(b, size);
    print(b, size);

}

Hope this helps!

Answer 3

use this :

void sort(struct books b[], int n)
{
    int i; int j;
    books t;
    for (i = 0; i < n; i++)
        for (j = i + 1; j < n ; j++)
            if (b[j].profit > b[i].profit)
            {
                t = b[j];
                b[j] = b[i];
                b[i] = t;
            }
}