49. 使用快速排序来实现对结构体的二级排序

//只一级排序，按成绩降序排名

#include <stdio.h>

typedef struct Stu
{
    char name[30];
    int num;
    float score;
}Stu;

void quickSort(Stu* p,int low,int high)//按成绩降序，
{
    if(low < high)
    {
        int l = low;
        int h = high;
        Stu pivot = p[low];

        /*让小于中轴在右半边，让大于中轴的在左半边*/
        while(l<h)
        {
           while(p[h].score <= pivot.score && h>l)//小于中轴 不移,留在原位，往前走直到碰见大于中轴的再移到左边。
           {
                h--;
           }
           p[l] = p[h];


           while(p[l].score >= pivot.score && l<h)//大于中轴 不移，留在原位，往前走直到碰见小于中轴的再移到右边
           {
              l++;
           }
           p[h] = p[l];

         }
        
         int pos = h;//此时lh相等
         p[pos] = pivot;


         quickSort(p,low,pos-1);
         quickSort(p,pos+1,high);
    }

}

int main(void)
{
    Stu arr[10] = {"zhangsan",1,60,
                  "lisi",2,70,
                  "wangwu",3,20,
                  "liudehua",4,55,
                  "liming",5,80,
                  "guodegang",6,100,
                  "guanyu",7,10,
                  "liubei",8,59,
                  "zhangxueyou",9,99,
                  "xiaoli",10,40};

    quickSort(arr,0,9);

    int i;
    for(i = 0;i<10;i++)
    {
        printf("%s,%d,%.0f
",arr[i].name,arr[i].num,arr[i].score);
    }

    return 0;
}

//实现二级排序，先按成绩降序排序，成绩相同再按学号升序排序。

#include <stdio.h>

typedef struct _Stu
{
    char name[30];
    int num;
    float score;
}Stu;

void quickSort(Stu* p,int low,int high)//按成绩降序，成绩如若相等，按学号升序
{
    if(low < high)
    {
        int l = low;
        int h = high;
        Stu pivot = p[low];

        /*让小于中轴在右半边，让大于中轴的在左半边*/
        while(l<h)
        {
           while(p[h].score <= pivot.score && h>l)
           {
               if(p[h].score < pivot.score)//成绩降序
               {
                   h--;
               }
               else if(p[h].score == pivot.score && p[h].num > pivot.num)//学号升序,大的留在右边
               {
                   h--;
               }
               else if((p[h].score == pivot.score && p[h].num < pivot.num))//学号升序，小的跳出循环往左移
               {
                   break;
               }
           }
           p[l] = p[h];


           while(p[l].score >= pivot.score && l<h)
           {
              if(p[l].score > pivot.score)//成绩降序
              {
                  l++;
              }
              else if(p[l].score == pivot.score && p[l].num < pivot.num)//学号升序
              {
                  l++;
              }
              else if(p[l].score == pivot.score && p[l].num > pivot.num)//学号升序，小的跳出循环往左移
              {
                  break;
              }
           }
           p[h] = p[l];
         }

         int pos = h;//此时lh相等
         p[pos] = pivot;


         quickSort(p,low,pos-1);
         quickSort(p,pos+1,high);
    }

}

int main(void)
{

    Stu arr[10] = {"zhangsan",5,80,
                  "lisi",11,80,
                  "wangwu",3,20,
                  "liudehua",4,55,
                  "liming",1,80,
                  "guodegang",6,100,
                  "guanyu",7,10,
                  "liubei",8,59,
                  "zhangxueyou",9,80,
                  "xiaoli",10,40};



    quickSort(arr,0,9);

    int i;
    for(i = 0;i<9;i++)
    {
        printf("%s,%d,%.0f
",arr[i].name,arr[i].num,arr[i].score);
    }

    return 0;
}