冒泡/选择/qsort排序

 

#include <stdio.h>
//冒泡排序

int bubble_Sort (int *arr, int size)
{
    int i = 0;
    int j = 0;
    for (i = 0; i < size-1; i++) //最多比较size-1个数
    {
        for (j = 0; j < size-1-i; j++)
            {
                if (arr[j + 1] < arr[j])
                {
                    int tmp = arr[j + 1];
                    arr[j + 1] = arr[j];
                    arr[j] = tmp;
                }
        }
    }
}

int main ()
{
    int arr[] = {1, 3, 8, 2, 6, 4, 7, 5};
    int size = sizeof(arr)/sizeof(int);
    bubble_Sort(arr, size);
    for (i =0; i < size; i++)
    {
        printf("%d", arr[i]);
    }
    printf("\n");
    return 0;
}

 

#include <stdio.h>
//选择排序

int choose_Sort (int *arr, int size)
{
    int i = 0;
    int j = 0;
    for (i = 0; i < size-1; i++) //最多比较size-1个数
    {
        for (j = i+1; j < size; j ++)
            {
                if (arr[i] > arr[j])
                {
                    int tmp = arr[j];
                    arr[j] = arr[i];
                    arr[i] = tmp;
                }
        }
    }
}

int main ()
{
    int arr[] = {1, 3, 8, 2, 6, 4, 7, 5};
    int size = sizeof(arr)/sizeof(int);
    choose_Sort(arr, size);
    for (i =0; i < size; i++)
    {
        printf("%d", arr[i]);
    }
    printf("\n");
    return 0;
}

 qsort 排序

#include <stdio.h>

int cmp(const void *a, const void *b)
{
    return *(int *)a > *(int *)b;
}

int main ()
{
    int arr[] = {1, 3, 6, 2, 2, 5, 4};
    qsort(arr, sizeof(arr)/sizeof(int), sizeof(*arr), cmp);  //从小到大
    //(数组名， 元素总个数， 单个元素内存， 比较)
}

 

#include <stdio.h>
int main ()
{
    int i = 0;
    int j = 0;
    int m = 0;
    int arr[] = {1, 3, 8, 2, 6, 4, 7, 5};
    for (i = 0; i < 7; i++)
    {
        for (j = 0; j < 7 - i; j ++)
            {
                if (arr[j + 1] < arr[j])
                {
                    int tmp = arr[j + 1];
                    arr[j + 1] = arr[j];
                    arr[j] = tmp;
                }
        }
    }
    for (m =0; m < 8; m++)
    {
        printf("%d", arr[m]);
    }
    printf("\n");
    return 0;
}