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

struct Student{
		char stunumber[5];
		int class;
		char name[10];
		float grade1;
		float grade2;
		float grade3;
		float sum;
		}students[3]={{"10001",11,"Zhang",99.5,88.5,89.5,99.5+88.5+99.5},
			{"10002",12,"Yang",77.9,56.5,87.5,77.9+56.5+87.5},
			{"10003",11,"Liang",92.5,99.0,60.5,92.5+99.0+60.5}};
void selection_sort(struct Student arr[], int n) {
    int i, j, min_idx;
    
    //一一检索每个结构体中class的值 
    for (i = 0; i < n-1; i++) {
        // 找到最小值的位置 
        min_idx = i;
        for (j = i+1; j < n; j++)
        {
		
            if (arr[j].class < arr[min_idx].class)
            {
                min_idx = j;
       		}
       		else if(arr[j].class == arr[min_idx].class)
       		{
       			if(arr[j].sum > arr[min_idx].sum)
       			{
       				min_idx=j;
				}
			}
		}
        // 通过交换位置实现排序
        struct Student temp = arr[min_idx];
        arr[min_idx] = arr[i];
        arr[i] = temp;
    }
}
int main(){
	int n=3;
	void selection_sort(struct Student arr[], int n); 
	
	int idx=-1;//查找待修改学生 
	char num_or_name[10];
	printf("请输入您要修改的学生学号或姓名\n");
	scanf("%s",&num_or_name);
	for(int i=0;i<3;i++)//检索学生 
	{
		if(strcmp(num_or_name, students[i].stunumber) == 0 || strcmp(num_or_name, students[i].name) == 0){
			idx=i;
			printf("idx is:%d\n",idx);
			break;
		}
	}
	
	if(idx==-1)//学生不存在 
	{
		printf("未查找到该学生!\n不予修改!\n");
		for(int i=0;i < 3;i++)
		{
			printf("%s %d %s %.1f %.1f %.1f \n", students[i].stunumber, students[i].class, students[i].name, students[i].grade1, students[i].grade2, students[i].grade3);
		}
		return 0;
	}
	printf("已查找到该学生!\n");
	printf("请输入修改后的信息\n"); 
	struct Student temp;//学生存在且输入修改后的信息 
	scanf("%s %d %s %f %f %f",&temp.stunumber,&temp.class,&temp.name,&temp.grade1,&temp.grade2,&temp.grade3);
	temp.sum=temp.grade1+temp.grade2+temp.grade3; 
	students[idx]=temp;
	
	selection_sort(students,3);//再一次排序
	printf("修改后的学生信息如下:\n");
	int class0=0;
	for(int i=0;i < 3;i++){
		printf("\n");
		if(students[i].class==class0)
		{
			printf("   %s %d %s %.1f %.1f %.1f ", students[i].stunumber, students[i].class, students[i].name, students[i].grade1, students[i].grade2, students[i].grade3);
		}
		if(class0!=students[i].class){
			class0=students[i].class;
			printf("%d ",class0);
			printf("%s %d %s %.1f %.1f %.1f ", students[i].stunumber, students[i].class, students[i].name, students[i].grade1, students[i].grade2, students[i].grade3);
		}
		if(strcmp(num_or_name, students[i].stunumber) == 0 || strcmp(num_or_name, students[i].name) == 0)
		{
			printf("modifiled");
		}
	}
}