用c语言写一个学生成绩管理系统，用链表

来存储学生成绩信息，要求能够实现添加学生信息、删除学生信息、修改学生成绩、查询学生成绩等功能。

好的，这是一个比较基本的数据结构应用题，使用链表存储学生成绩信息是比较好的选择。以下是一个实现该功能的C语言代码：

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

#define MAX_NAME_LEN 20

typedef struct student_t {
    char name[MAX_NAME_LEN];
    int score;
    struct student_t *next;
} Student;

Student *create_student(char *name, int score)
{
    Student *s = (Student *)malloc(sizeof(Student));
    if (s != NULL) {
        strcpy(s->name, name);
        s->score = score;
        s->next = NULL;
    }
    return s;
}

Student *find_student(Student *head, char *name)
{
    Student *s = head;
    while (s != NULL) {
        if (strcmp(s->name, name) == 0) {
            return s;
        }
        s = s->next;
    }
    return NULL;
}

int add_student(Student **head, char *name, int score)
{
    Student *new_student = create_student(name, score);
    if (new_student == NULL) {
        return -1;
    }
    new_student->next = *head;
    *head = new_student;
    return 0;
}

int delete_student(Student **head, char *name)
{
    Student *prev = NULL;
    Student *curr = *head;

    while (curr != NULL) {
        if (strcmp(curr->name, name) == 0) {
            if (prev != NULL) {
                prev->next = curr->next;
            } else {
                *head = curr->next;
            }
            free(curr);
            return 0;
        }
        prev = curr;
        curr = curr->next;
    }
    return -1;
}

int modify_student_score(Student *head, char *name, int new_score)
{
    Student *student = find_student(head, name);
    if (student != NULL) {
        student->score = new_score;
        return 0;
    }
    return -1;
}

void print_student_info(Student *s)
{
    printf("%s\t%d\n", s->name, s->score);
}

void print_all_students(Student *head)
{
    Student *s = head;
    while (s != NULL) {
        print_student_info(s);
        s = s->next;
    }
}

void free_all_students(Student *head)
{
    Student *s = head;
    while (s != NULL) {
        Student *tmp = s->next;
        free(s);
        s = tmp;
    }
}

int main()
{
    Student *head = NULL;

    add_student(&head, "Alice", 90);
    add_student(&head, "Bob", 85);
    add_student(&head, "Charlie", 92);

    print_all_students(head);

    modify_student_score(head, "Bob", 95);

    delete_student(&head, "Charlie");

    print_all_students(head);

    free_all_students(head);

    return 0;
}

这是一个基本的链表实现。你可以根据需求进行扩展，比如增加文件或数据库读写功能，或者实现更复杂的排序等操作。