用结构体输入各学生信息，各学生按学号和总成绩分别升序排

下面是一个示例代码，用结构体输入学生信息并按照学号和总成绩排序：

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

#define MAX_STUDENTS 100

struct student {
    char id[10];
    char name[20];
    int score1;
    int score2;
    int score3;
    int total;
};

int main() {
    struct student students[MAX_STUDENTS];
    int n = 0;

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

    // 输入每个学生的信息
    for (int i = 0; i < n; i++) {
        printf("Enter student %d's ID, name, score1, score2, score3: ", i+1);
        scanf("%s %s %d %d %d", students[i].id, students[i].name,
              &students[i].score1, &students[i].score2, &students[i].score3);
        students[i].total = students[i].score1 + students[i].score2 + students[i].score3;
    }

    // 按学号升序排序
    for (int i = 0; i < n-1; i++) {
        for (int j = i+1; j < n; j++) {
            if (strcmp(students[i].id, students[j].id) > 0) {
                struct student temp = students[i];
                students[i] = students[j];
                students[j] = temp;
            }
        }
    }

    printf("\nSorted by ID:\n");
    printf("ID\tName\tScore1\tScore2\tScore3\tTotal\n");
    for (int i = 0; i < n; i++) {
        printf("%s\t%s\t%d\t%d\t%d\t%d\n", students[i].id, students[i].name,
               students[i].score1, students[i].score2, students[i].score3, students[i].total);
    }

    // 按总成绩升序排序
    for (int i = 0; i < n-1; i++) {
        for (int j = i+1; j < n; j++) {
            if (students[i].total > students[j].total) {
                struct student temp = students[i];
                students[i] = students[j];
                students[j] = temp;
            }
        }
    }

    printf("\nSorted by total score:\n");
    printf("ID\tName\tScore1\tScore2\tScore3\tTotal\n");
    for (int i = 0; i < n; i++) {
        printf("%s\t%s\t%d\t%d\t%d\t%d\n", students[i].id, students[i].name,
               students[i].score1, students[i].score2, students[i].score3, students[i].total);
    }

    return 0;
}

在这个示例代码中，我们使用了一个结构体 `student` 来表示每个学生的信息。每个学生包括学号、姓名、三门科目的成绩以及总成绩。我们首先输入每个学生的信息，然后按照学号进行升序排序并输出，接着按照总成绩进行升序排序并输出。在排序过程中，我们使用了 `strcmp` 函数来比较两个学生的学号的大小关系。