C语言 day12

qsort排序

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <string.h>

int com_num(const void* n1, const void* n2) {

    return *(int*)n1 - *(int*)n2;
}


void test1() {

    int arr[] = { 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 };
    int sz = sizeof(arr) / sizeof(arr[0]);
    qsort(arr, sz, sizeof(arr[0]), com_num);
    for (int i = 0;i < sz;i++) {

        printf("%d ", arr[i]);
    }
}

struct Student
{
    char name[10];
    int age;
};

int com_age(const void* s1, const void * s2)
{
    return ((struct Student*)s1)->age - ((struct Student*)s2)->age;
}

int com_name(const void* s1, const void* s2)
{
    return strcmp(((struct Student*)s1)->name, ((struct Student*)s2)->name);
}

void test2()
{
    struct Student stu[3] = { {"zhangsan", 29},{"lisi", 22},{"wangwu", 21} };
    int sz = sizeof(stu) / sizeof(stu[0]);
    //qsort(stu, sz, sizeof(stu[0]), com_age);
    qsort(stu, sz, sizeof(stu[0]), com_name);
    for (int i = 0; i < sz; i++)
    {
        printf("%s %d\n",stu[i].name, stu[i].age);
    }
}



//快排  qsort
int main() {
    // test1();
    test2();
    return 0;
}