定义一个结构体，包含学生学号、姓名性别和5门课成绩再根据学号查找学生输入5门成绩

好的，以下是定义结构体和查找学生的代码：

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

#define MAX_STUDENTS 100

struct Student {
    int id;
    char name[20];
    char gender[10];
    float grades[5];
};

int main() {
    struct Student students[MAX_STUDENTS];
    int num_students = 0;

    // 添加学生信息
    students[num_students].id = 1001;
    strcpy(students[num_students].name, "张三");
    strcpy(students[num_students].gender, "男");
    students[num_students].grades[0] = 80.0;
    students[num_students].grades[1] = 85.5;
    students[num_students].grades[2] = 90.0;
    students[num_students].grades[3] = 87.5;
    students[num_students].grades[4] = 92.0;
    num_students++;

    students[num_students].id = 1002;
    strcpy(students[num_students].name, "李四");
    strcpy(students[num_students].gender, "女");
    students[num_students].grades[0] = 75.0;
    students[num_students].grades[1] = 82.5;
    students[num_students].grades[2] = 88.0;
    students[num_students].grades[3] = 90.5;
    students[num_students].grades[4] = 85.0;
    num_students++;

    // 根据学号查找学生
    int search_id;
    printf("请输入学生学号：");
    scanf("%d", &search_id);

    int i;
    for (i = 0; i < num_students; i++) {
        if (students[i].id == search_id) {
            printf("学生姓名：%s\n", students[i].name);
            printf("学生性别：%s\n", students[i].gender);
            printf("学生成绩：");
            int j;
            for (j = 0; j < 5; j++) {
                printf("%.1f ", students[i].grades[j]);
            }
            printf("\n");
            break;
        }
    }

    if (i == num_students) {
        printf("未找到该学生！\n");
    }

    return 0;
}

希望这个代码能够帮到你！