给出n个学生的考试成绩表，每条信息由姓名和分数组成，试设计一个算法： （1） 按分数高低次序，打印出每个学生在考试中获得的名次，分数相同的为同一名次； （2） 按名次列出每个学生的姓名与分数。用c语言代码实现

以下是基于冒泡排序的实现代码，时间复杂度为O(n^2)：

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

typedef struct {
    char name[20];
    int score;
    int rank;
} Student;

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

void print_rank_by_score(Student students[], int n) {
    int rank = 1;
    int i;
    students[0].rank = 1;
    for (i = 1; i < n; i++) {
        if (students[i].score == students[i-1].score) {
            students[i].rank = students[i-1].rank;
        } else {
            students[i].rank = i + 1;
            rank = i + 1;
        }
    }
    for (i = 0; i < n; i++) {
        printf("%s的名次是%d\n", students[i].name, students[i].rank);
    }
}

void print_score_by_rank(Student students[], int n) {
    int i;
    for (i = 0; i < n; i++) {
        printf("第%d名是%s，分数是%d\n", students[i].rank, students[i].name, students[i].score);
    }
}

int main() {
    Student students[] = {
        {"张三", 90},
        {"李四", 80},
        {"王五", 80},
        {"赵六", 70},
        {"钱七", 60},
    };
    int n = sizeof(students) / sizeof(Student);
    sort_by_score(students, n);
    print_rank_by_score(students, n);
    print_score_by_rank(students, n);
    return 0;
}

其中，`sort_by_score`函数按照成绩从高到低排序；`print_rank_by_score`函数打印出每个学生的排名；`print_score_by_rank`函数按照排名从1到n列出每个学生的姓名和分数。