C语言一道简单题目，都做不出来，难受啊，一定要多写代码啊

1.用户从屏幕输入每个学生的成绩，格式如下：学号 成绩  换行 。学号为整数。范围为1-50，成绩为浮点数。

2.如果用户的学号输入有重复，表明前面输入有误，用新的成绩覆盖之。

3.用户最多只能输入50个学生的成绩，如果已经输入了50个，则表明成绩输入完毕。

4.如果用户的学号输入-1，则表明成绩输入完毕。

5.程序将所以学生的成绩进行排序后，按照成绩的高低进行打印，打印格式如下：学号 成绩 换行

举例

1   50

2   60

3   55

2   80

 -1

Result:

2  80

3  55

1  50

最后是chatgpt写的，满足要求的，附上源码

#include 

#define MAX_STUDENTS 50

struct Student 
{
    int id;
    float score;
};

void swap(struct Student *a, struct Student *b) 
{
    struct Student temp = *a;
    *a = *b;
    *b = temp;
}

void sortStudents(struct Student students[], int count) 
{
    for (int i = 0; i < count - 1; i++) {
        for (int j = 0; j < count - i - 1; j++) {
            if (students[j].score < students[j + 1].score) {
                swap(&students[j], &students[j + 1]);
            }
        }
    }
}

int main() 
{
    struct Student students[MAX_STUDENTS];
    int count = 0;
    
    printf("Enter student grades (id score) or -1 to finish:\n");
    
    while (1) {
        int id;
        float score;
        
        scanf("%d", &id);
        
        if (id == -1) {
            break;
        }
        
        scanf("%f", &score);
        
        // Check for duplicate id
        int duplicateIndex = -1;
        for (int i = 0; i < count; i++) {
            if (students[i].id == id) {
                duplicateIndex = i;
                break;
            }
        }
        
        if (duplicateIndex != -1) {
            students[duplicateIndex].score = score;
        } else {
            students[count].id = id;
            students[count].score = score;
            count++;
        }
        
        if (count >= MAX_STUDENTS) {
            printf("Maximum number of students reached.\n");
            break;
        }
    }
    
    sortStudents(students, count);
    
    printf("Result:\n");
    
    for (int i = 0; i < count; i++) {
        printf("%d\t%.2f\n", students[i].id, students[i].score);
    }
    
    return 0;
}

运行结果如下：

叫chatgpt用链表实现，也满足了要求

#include 
#include 

struct Node {
    int id;
    float score;
    struct Node* next;
};

struct Node* createNode(int id, float score) {
    struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
    newNode->id = id;
    newNode->score = score;
    newNode->next = NULL;
    return newNode;
}

struct Node* insertOrUpdate(struct Node* head, int id, float score) {
    struct Node* newNode = createNode(id, score);

    if (head == NULL) {
        return newNode;
    }

    if (head->id == id) {
        head->score = score;
        free(newNode);
        return head;
    }

    struct Node* curr = head;
    struct Node* prev = NULL;

    while (curr != NULL) {
        if (curr->id == id) {
            prev->next = newNode;
            newNode->next = curr->next;
            free(curr);
            return head;
        }
        prev = curr;
        curr = curr->next;
    }

    prev->next = newNode;
    return head;
}

void swap(struct Node* a, struct Node* b) {
    int tempId = a->id;
    float tempScore = a->score;
    a->id = b->id;
    a->score = b->score;
    b->id = tempId;
    b->score = tempScore;
}

void sortStudents(struct Node* head) {
    int swapped;
    struct Node* ptr1;
    struct Node* lptr = NULL;

    if (head == NULL) {
        return;
    }

    do {
        swapped = 0;
        ptr1 = head;

        while (ptr1->next != lptr) {
            if (ptr1->score < ptr1->next->score) {
                swap(ptr1, ptr1->next);
                swapped = 1;
            }
            ptr1 = ptr1->next;
        }
        lptr = ptr1;
    } while (swapped);
}

void printStudents(struct Node* head) {
    printf("Result:\n");

    while (head != NULL) {
        printf("%d\t%.2f\n", head->id, head->score);
        head = head->next;
    }
}

void freeList(struct Node* head) {
    struct Node* temp;

    while (head != NULL) {
        temp = head;
        head = head->next;
        free(temp);
    }
}

int main() {
    struct Node* head = NULL;
    int count = 0;
    
    printf("Enter student grades (id score) or -1 to finish:\n");
    
    while (1) {
        int id;
        float score;
        
        scanf("%d", &id);
        
        if (id == -1) {
            break;
        }
        
        scanf("%f", &score);
        
        if (id < 1 || id > 50) {
            printf("Invalid student ID. Please enter a valid ID (1-50).\n");
            continue;
        }
        
        head = insertOrUpdate(head, id, score);
        count++;
        
        if (count >= 50) {
            printf("Maximum number of students reached.\n");
            break;
        }
    }
    
    sortStudents(head);
    printStudents(head);
    freeList(head);
    
    return 0;
}

 运行结果如下：