<>代码>qsort() 是你重新研究的功能。 你把它称作你的系列数据、该阵列中的内容数目、每个要素的规模和比较功能。

它做的是魔法和你阵列。 例如:

#include <stdio.h>
#include <stdlib.h>
int comp (const void * elem1, const void * elem2) 
{
    int f = *((int*)elem1);
    int s = *((int*)elem2);
    if (f > s) return  1;
    if (f < s) return -1;
    return 0;
}
int main(int argc, char* argv[]) 
{
    int x[] = {4,5,2,3,1,0,9,8,6,7};

    qsort (x, sizeof(x)/sizeof(*x), sizeof(*x), comp);

    for (int i = 0 ; i < 10 ; i++)
        printf ("%d ", x[i]);

    return 0;
}

C.C++ 标准图书馆<stdlib.h> <代码>qsort功能。

This is not the best quick sort implementation in the world but it fast enough and VERY EASY to be used... the formal syntax of qsort is:

qsort(<arrayname>,<size>,sizeof(<elementsize>),compare_function);

The only thing that you need to implement is the compare_function, which takes in two arguments of type "const void", which can be cast to appropriate data structure, and then return one of these three values:

• negative, if a should be before b
• 0, if a equal to b
• positive, if a should be after b

页: 1 a. 比较分类:

simply cast a and b to integers if x < y,x-y is negative, x == y, x-y = 0, x > y, x-y is positive x-y is a shortcut way to do it :) reverse *x - *y to *y - *x for sorting in decreasing/reverse order

int compare_function(const void *a,const void *b) {
int *x = (int *) a;
int *y = (int *) b;
return *x - *y;
}

2. 比较显示:

For comparing string, you need strcmp function inside <string.h> lib. strcmp will by default return -ve,0,ve appropriately... to sort in reverse order, just reverse the sign returned by strcmp

#include <string.h>
int compare_function(const void *a,const void *b) {
return (strcmp((char *)a,(char *)b));
}

3.比较浮动点号码:

int compare_function(const void *a,const void *b) {
double *x = (double *) a;
double *y = (double *) b;
// return *x - *y; // this is WRONG...
if (*x < *y) return -1;
else if (*x > *y) return 1; return 0;
}

4. 比较基于关键的记录:

Sometimes you need to sort a more complex stuffs, such as record. Here is the simplest way to do it using qsort library.

typedef struct {
int key;
double value;
} the_record;

int compare_function(const void *a,const void *b) {
the_record *x = (the_record *) a;
the_record *y = (the_record *) b;
return x->key - y->key;
}

确切地说,qsort(>>)是一种执行(不一定像其名称可能暗示的那样迅速)。

Try man 3 qsort or have a Read at http://linux.die.net/man/3/qsort。

虽然在标准图书馆没有准确,但https://github.com/swenson/sort 你们只有两处主人档案,可以包括获取各种经红的快速通道,例如:

#define SORT_NAME int64
#define SORT_TYPE int64_t
#define SORT_CMP(x, y) ((x) - (y))
#include "sort.h"
/* You now have access to int64_quick_sort, int64_tim_sort, etc., e.g., */
int64_quick_sort(arr, 128); /* Assumes you have some int *arr or int arr[128]; */

这应至少是标准图书馆<代码>qsort<>/code>的两倍,因为它没有使用功能点,而且还有其他许多类型的算法选择。

在C89,在基本上每个C汇编者中开展工作。

http://www.un.org。

I think you are looking for qsort.
qsort function is the implementation of quicksort algorithm found in stdlib.h in C/C++.

此处称为<代码>qsort功能:

void qsort(void *base, size_t nmemb, size_t size,int (*compar)(const void *, const void *));

List of arguments:

base: pointer to the first element or base address of the array
nmemb: number of elements in the array
size: size in bytes of each element
compar: a function that compares two elements

此处是使用<条码>qsort<>/条码>来分类一个阵列的代码例子:

#include <stdio.h>
#include <stdlib.h>

int arr[] = { 33, 12, 6, 2, 76 };

// compare function, compares two elements
int compare (const void * num1, const void * num2) {
   if(*(int*)num1 > *(int*)num2)
    return 1;
   else
    return -1;
}

int main () {
   int i;

   printf("Before sorting the array: 
");
   for( i = 0 ; i < 5; i++ ) {
      printf("%d ", arr[i]);
   }
   // calling qsort
   qsort(arr, 5, sizeof(int), compare);

   printf("
After sorting the array: 
");
   for( i = 0 ; i < 5; i++ ) {   
      printf("%d ", arr[i]);
   }
  
   return 0;
}

You can type man 3 qsort in Linux/Mac terminal to get a detailed info about qsort.
Link to qsort man page

使用qsort( in <stdlib.h>。

@paxdiablo The qsort() function conforms to ISO/IEC 9899:1990 (``ISO C90 ).

<代码>stdlib.h有几种分类功能。 您可以做以下工作:

• heapsort
• quicksort
• mergesort

GNU qsort sources in adlib show that it is Immediatesort.