需要实现显示学生成绩信息，显示C语言的最高分，显示C语言的最低分，显示C语言的平均分，从高到底显示C语言成绩，按学号查找C语言成绩，按姓名查找C语言成绩等功能的代码

下面是一个简单的学生成绩管理系统的代码，实现了显示学生信息、C语言成绩的最高分、最低分、平均分、从高到低排序、按学号查找和按姓名查找等功能。

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

#define MAX_STUDENT 100

struct Student {
    char name[20];
    int id;
    float c_score;
};

void display_student(struct Student s);
float get_c_highest(struct Student students[], int n);
float get_c_lowest(struct Student students[], int n);
float get_c_average(struct Student students[], int n);
void sort_by_c_score_desc(struct Student students[], int n);
void search_by_id(struct Student students[], int n, int id);
void search_by_name(struct Student students[], int n, char name[]);

int main() {
    struct Student students[MAX_STUDENT];
    int n, i, choice, id;
    char name[20];

    printf("Enter the number of students (max %d): ", MAX_STUDENT);
    scanf("%d", &n);

    for (i = 0; i < n; i++) {
        printf("Enter the name, id, and C score of student %d: ", i+1);
        scanf("%s %d %f", students[i].name, &students[i].id, &students[i].c_score);
    }

    while (1) {
        printf("\n1. Display all students\n");
        printf("2. Display C highest score\n");
        printf("3. Display C lowest score\n");
        printf("4. Display C average score\n");
        printf("5. Sort by C score (descending order)\n");
        printf("6. Search by id\n");
        printf("7. Search by name\n");
        printf("8. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                printf("\n%-20s%-10s%-10s\n", "Name", "ID", "C score");
                for (i = 0; i < n; i++) {
                    display_student(students[i]);
                }
                break;
            case 2:
                printf("\nC highest score: %.2f\n", get_c_highest(students, n));
                break;
            case 3:
                printf("\nC lowest score: %.2f\n", get_c_lowest(students, n));
                break;
            case 4:
                printf("\nC average score: %.2f\n", get_c_average(students, n));
                break;
            case 5:
                sort_by_c_score_desc(students, n);
                printf("\n%-20s%-10s%-10s\n", "Name", "ID", "C score");
                for (i = 0; i < n; i++) {
                    display_student(students[i]);
                }
                break;
            case 6:
                printf("\nEnter student id to search: ");
                scanf("%d", &id);
                search_by_id(students, n, id);
                break;
            case 7:
                printf("\nEnter student name to search: ");
                scanf("%s", name);
                search_by_name(students, n, name);
                break;
            case 8:
                exit(0);
            default:
                printf("\nInvalid choice!\n");
        }
    }

    return 0;
}

void display_student(struct Student s) {
    printf("%-20s%-10d%-10.2f\n", s.name, s.id, s.c_score);
}

float get_c_highest(struct Student students[], int n) {
    int i;
    float highest = students[0].c_score;
    for (i = 1; i < n; i++) {
        if (students[i].c_score > highest) {
            highest = students[i].c_score;
        }
    }
    return highest;
}

float get_c_lowest(struct Student students[], int n) {
    int i;
    float lowest = students[0].c_score;
    for (i = 1; i < n; i++) {
        if (students[i].c_score < lowest) {
            lowest = students[i].c_score;
        }
    }
    return lowest;
}

float get_c_average(struct Student students[], int n) {
    int i;
    float sum = 0;
    for (i = 0; i < n; i++) {
        sum += students[i].c_score;
    }
    return sum / n;
}

void sort_by_c_score_desc(struct Student students[], int n) {
    int i, j;
    struct Student temp;
    for (i = 0; i < n-1; i++) {
        for (j = i+1; j < n; j++) {
            if (students[i].c_score < students[j].c_score) {
                temp = students[i];
                students[i] = students[j];
                students[j] = temp;
            }
        }
    }
}

void search_by_id(struct Student students[], int n, int id) {
    int i;
    for (i = 0; i < n; i++) {
        if (students[i].id == id) {
            printf("\n%-20s%-10d%-10.2f\n", students[i].name, students[i].id, students[i].c_score);
            return;
        }
    }
    printf("\nStudent with id %d not found!\n", id);
}

void search_by_name(struct Student students[], int n, char name[]) {
    int i;
    for (i = 0; i < n; i++) {
        if (strcmp(students[i].name, name) == 0) {
            printf("\n%-20s%-10d%-10.2f\n", students[i].name, students[i].id, students[i].c_score);
        }
    }
}