库函数qsort使用示范

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

struct Struction
{
    double one;
    int another;
};

int CmpInt_1(const void *a,const void *b)
{
    return *(int*)a - *(int*)b;
}

int CmpInt_2(const void *a,const void *b)
{
    int *c = (int *)a;
    int *d = (int *)b;

    if(*(c+0) != *(d+0))
    {
        return *(c+0) - *(d+0);
    }
    else
    {
        return *(c+1) - *(d+1);
    }
}

int CmpStruction(const void *a,const void *b)
{
    struct Struction *c = (struct Struction *)a;
    struct Struction *d = (struct Struction *)b;

    if(c->one != d->one)
    {
        return  c->one > d-> one ? 1 : 0;
    }
    else
    {
        return c->another > d-> another ? 1 : 0;
    }
}

int CmpString(const void *a,const void *b)
{
    return strcmp((char*)a,(char*)b);
}

int main()
{
    int i,j;

    //sort int*
    int TestArray_1[10] = {718,224,3332,4443,55,31,66,79,90,7};
    qsort(TestArray_1,10,sizeof(int),CmpInt_1);

    for(i = 0; i < 10; i ++)
    {
        printf("%d ",TestArray_1[i]);
    }
    printf("

");


    //sort int**
    int TestArray_2[5][2] = {{0,1},{2,7},{-4,99},{1,900},{2,423}};
    qsort(TestArray_2,5,sizeof(TestArray_2[0]),CmpInt_2);

    for(i = 0; i < 5; i ++)
    {
        for(j = 0; j < 2; j ++)
        {
            printf("%d ",TestArray_2[i][j]);
        }
        printf("
");
    }
    printf("

");

    //sort struct with two variable
    struct Struction *TestArray_3 = malloc(5*sizeof(struct Struction));
    TestArray_3[0].one = 1.1;
    TestArray_3[0].another = 18;
    TestArray_3[1].one = 43;
    TestArray_3[1].another = -99;
    TestArray_3[2].one = 1.1;
    TestArray_3[2].another = 900;
    TestArray_3[3].one = 3;
    TestArray_3[3].another = 6;
    TestArray_3[4].one = 2;
    TestArray_3[4].another = 4;

    qsort(TestArray_3,5,sizeof(struct Struction),CmpStruction);
    for(i = 0; i < 5; i ++)
    {
        printf("%lf %d
",TestArray_3[i].one,TestArray_3[i].another);
    }
    printf("

");
    
    //sort string
    char TestArray_4[5][100];
    strcpy(TestArray_4[0],"Asurudo");
    strcpy(TestArray_4[1],"Lokianyu");
    strcpy(TestArray_4[2],"Hatsune");
    strcpy(TestArray_4[3],"Miku");
    strcpy(TestArray_4[4],"Aqours");
    
    qsort(TestArray_4,5,sizeof(TestArray_4[0]),CmpString);
    for(i = 0;i < 5;i ++)
    {
        puts(TestArray_4[i]);
    }
    
    return 0;
}