定义结构体变量，用它表示考生的学号、姓名（用英文表示）以及语文、数学、外语成绩。输入两个考生的信息和各门课成绩并比较（按总分进行高低排序；当总分相同时，依次按语、数、外的顺序排序）。

定义一个结构体变量，包含考生的学号、姓名以及语文、数学、外语成绩。可以使用以下代码：

struct student {
int id; // 学号
char name[20]; // 姓名
float chinese; // 语文成绩
float math; // 数学成绩
float english; // 外语成绩
float total; // 总分
};

然后，输入两个考生的信息和各门课成绩，并计算总分。可以使用以下代码：

struct student s1, s2;
scanf("%d %s %f %f %f", &s1.id, s1.name, &s1.chinese, &s1.math, &s1.english);
scanf("%d %s %f %f %f", &s2.id, s2.name, &s2.chinese, &s2.math, &s2.english);

s1.total = s1.chinese + s1.math + s1.english;
s2.total = s2.chinese + s2.math + s2.english;

接下来，按照总分进行高低排序。如果总分相同，则按照语、数、外的顺序排序。可以使用以下代码：

if (s1.total > s2.total) {
printf("%d %s %.1f %.1f %.1f %.1f\n", s1.id, s1.name, s1.chinese, s1.math, s1.english, s1.total);
printf("%d %s %.1f %.1f %.1f %.1f\n", s2.id, s2.name, s2.chinese, s2.math, s2.english, s2.total);
} else if (s1.total < s2.total) {
printf("%d %s %.1f %.1f %.1f %.1f\n", s2.id, s2.name, s2.chinese, s2.math, s2.english, s2.total);
printf("%d %s %.1f %.1f %.1f %.1f\n", s1.id, s1.name, s1.chinese, s1.math, s1.english, s1.total);
} else {
if (s1.chinese > s2.chinese) {
printf("%d %s %.1f %.1f %.1f %.1f\n", s1.id, s1.name, s1.chinese, s1.math, s1.english, s1.total);
printf("%d %s %.1f %.1f %.1f %.1f\n", s2.id, s2.name, s2.chinese, s2.math, s2.english, s2.total);
} else if (s1.chinese < s2.chinese) {
printf("%d %s %.1f %.1f %.1f %.1f\n", s2.id, s2.name, s2.chinese, s2.math, s2.english, s2.total);
printf("%d %s %.1f %.1f %.1f %.1f\n", s1.id, s1.name, s1.chinese, s1.math, s1.english, s1.total);
} else {
if (s1.math > s2.math) {
printf("%d %s %.1f %.1f %.1f %.1f\n", s1.id, s1.name, s1.chinese, s1.math, s1.english, s1.total);
printf("%d %s %.1f %.1f %.1f %.1f\n", s2.id, s2.name, s2.chinese, s2.math, s2.english, s2.total);
} else if (s1.math < s2.math) {
printf("%d %s %.1f %.1f %.1f %.1f\n", s2.id, s2.name, s2.chinese, s2.math, s2.english, s2.total);
printf("%d %s %.1f %.1f %.1f %.1f\n", s1.id, s1.name, s1.chinese, s1.math, s1.english, s1.total);
} else {
if (s1.english > s2.english) {
printf("%d %s %.1f %.1f %.1f %.1f\n", s1.id, s1.name, s1.chinese, s1.math, s1.english, s1.total);
printf("%d %s %.1f %.1f %.1f %.1f\n", s2.id, s2.name, s2.chinese, s2.math, s2.english, s2.total);
} else {
printf("%d %s %.1f %.1f %.1f %.1f\n", s2.id, s2.name, s2.chinese, s2.math, s2.english, s2.total);
printf("%d %s %.1f %.1f %.1f %.1f\n", s1.id, s1.name, s1.chinese, s1.math, s1.english, s1.total);
}
}
}
}

这段代码中，首先判断两个考生的总分大小关系，如果s1的总分大于s2的总分，则输出s1的信息在前，否则输出s2的信息在前。如果两个考生的总分相同，则按照语、数、外的顺序进行比较，输出信息。