用c语言写学生成绩管理系统，查询时可实现按姓名、按学号查询，输入任意的一个课程名(如数学)和一个分数段(如 60--70)，统计出在此分数段的学生情况。C

好的，这是一个比较典型的学生成绩管理系统，下面是一个简单的代码示例：

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

#define MAX_STUDENT 100

typedef struct {
    char name[20];
    int id;
    int math;
    int english;
    int physics;
} Student;

Student students[MAX_STUDENT];
int num_students = 0;

int search_by_name(char *name) {
    int i;
    for (i = 0; i < num_students; i++) {
        if (strcmp(students[i].name, name) == 0) {
            return i;
        }
    }
    return -1;
}

int search_by_id(int id) {
    int i;
    for (i = 0; i < num_students; i++) {
        if (students[i].id == id) {
            return i;
        }
    }
    return -1;
}

void add_student() {
    if (num_students >= MAX_STUDENT) {
        printf("Too many students, cannot add more.\n");
        return;
    }
    Student *s = &students[num_students++];
    printf("Please enter student information:\n");
    printf("Name: ");
    scanf("%s", s->name);
    printf("ID: ");
    scanf("%d", &s->id);
    printf("Math score: ");
    scanf("%d", &s->math);
    printf("English score: ");
    scanf("%d", &s->english);
    printf("Physics score: ");
    scanf("%d", &s->physics);
}

void print_student(Student *s) {
    printf("Name: %s\n", s->name);
    printf("ID: %d\n", s->id);
    printf("Math score: %d\n", s->math);
    printf("English score: %d\n", s->english);
    printf("Physics score: %d\n", s->physics);
}

void list_students() {
    int i;
    for (i = 0; i < num_students; i++) {
        printf("Student %d:\n", i+1);
        print_student(&students[i]);
    }
}

void search_student() {
    int option, id, index;
    char name[20];
    printf("Please select search option:\n");
    printf("1. Search by name\n");
    printf("2. Search by ID\n");
    scanf("%d", &option);
    switch (option) {
        case 1:
            printf("Please enter student name:\n");
            scanf("%s", name);
            index = search_by_name(name);
            break;
        case 2:
            printf("Please enter student ID:\n");
            scanf("%d", &id);
            index = search_by_id(id);
            break;
        default:
            printf("Invalid option.\n");
            return;
    }
    if (index == -1) {
        printf("Student not found.\n");
    } else {
        printf("Student found:\n");
        print_student(&students[index]);
    }
}

void search_by_score() {
    char subject[20];
    int low, high, i, count = 0;
    printf("Please enter subject name:\n");
    scanf("%s", subject);
    printf("Please enter low score:\n");
    scanf("%d", &low);
    printf("Please enter high score:\n");
    scanf("%d", &high);
    printf("Students with %s score between %d and %d:\n", subject, low, high);
    for (i = 0; i < num_students; i++) {
        int score = 0;
        if (strcmp(subject, "math") == 0) {
            score = students[i].math;
        } else if (strcmp(subject, "english") == 0) {
            score = students[i].english;
        } else if (strcmp(subject, "physics") == 0) {
            score = students[i].physics;
        }
        if (score >= low && score <= high) {
            print_student(&students[i]);
            count++;
        }
    }
    if (count == 0) {
        printf("No students found with %s score between %d and %d.\n", subject, low, high);
    }
}

int main() {
    int option;
    while (1) {
        printf("Please select an option:\n");
        printf("1. Add student\n");
        printf("2. List all students\n");
        printf("3. Search student\n");
        printf("4. Search by score\n");
        printf("5. Quit\n");
        scanf("%d", &option);
        switch (option) {
            case 1:
                add_student();
                break;
            case 2:
                list_students();
                break;
            case 3:
                search_student();
                break;
            case 4:
                search_by_score();
                break;
            case 5:
                return 0;
            default:
                printf("Invalid option.\n");
                break;
        }
    }
}

这个程序中，我们使用了一个 `Student` 结构体来表示学生，其中包含了姓名、学号、数学、英语、物理三门科目的成绩。我们使用一个数组 `students` 来存储所有学生的信息，还有一个整数变量 `num_students` 表示当前学生数量。

程序的主要功能包括：

- 添加学生信息，使用 `add_student` 函数实现；
- 列出所有学生信息，使用 `list_students` 函数实现；
- 按姓名或学号查询学生信息，使用 `search_student` 函数实现；
- 按科目和分数段查询学生信息，使用 `search_by_score` 函数实现。

在查询学生信息时，我们使用了两个简单的查找函数 `search_by_name` 和 `search_by_id`，它们分别按姓名和学号进行查找，并返回找到的学生在数组中的索引。在查询科目和分数段时，我们使用了一个循环遍历所有学生，对每个学生的指定科目成绩进行比较，符合条件的就输出。

注意到这个程序还有一些简单的输入输出和错误处理，这些内容可以根据实际需要进行修改和完善。