C语言 链表实现 学生成绩排名

题    源

本题来自于牛客网：
https://www.nowcoder.com/practice/0383714a1bb749499050d2e0610418b1?tpId=40&tqId=21333&tPage=1&rp=1&ru=/ta/kaoyan&qru=/ta/kaoyan/question-ranking

题 目 描 述

查找和排序

题目：输入任意（用户，成绩）序列，可以获得成绩从高到低或从低到高的排列,相同成绩都按先录入排列在前的规则处理。

   例示：

   jack      70

   peter     96

   Tom       70

   smith     67

   从高到低  成绩            

   peter     96    

   jack      70    

   Tom       70    

   smith     67    

   从低到高

   smith     67  

   Tom       70    

   jack      70    

   peter     96      

输入描述:

输入多行，先输入要排序的人的个数，然后输入排序方法0（降序）或者1（升序）再分别输入他们的名字和成绩，以一个空格隔开

输出描述:

按照指定方式输出名字和成绩，名字和成绩之间以一个空格隔开

示例1

输入

3

0

fang 90

yang 50

ning 70

输出

fang 90

ning 70

yang 50

  C 代 码  

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

typedef struct Student
{
char name[20];
int score;
struct Stu *next;
}Stu;

int count_nodes_of_a_list(Stu * list)
{
Stu * tmp = list;
int count = 0;
while(tmp){
count++;
tmp = tmp->next;
}
printf("%d nodes in total\n",count);
return count;
}

void node_print(Stu * node)
{
printf("%s-->%d\n",node->name,node->score);
}

Stu * make_a_list(Stu *head, Stu* tmp)
{
if(tmp != NULL){
tmp->next = head;
head = tmp;
}
return head;
}

Stu * up(Stu *head,Stu *tmp)
{
if(head->score == 0){
return tmp;
}else if((head->score > tmp->score) || (head->score == tmp->score)){
tmp->next = head;
return tmp;
}else{
Stu *pre, *cur = head;
while(cur && (cur->score< tmp->score || cur->score==tmp->score)){
pre = cur;
cur = cur->next;
}
if(cur == NULL){
pre->next = tmp;
}else{
tmp->next = cur;
pre->next = tmp;
}

return head;
}
}

Stu * down(Stu *head,Stu *tmp)
{
if(head->score == 0){
return tmp;
}else if(head->score < tmp->score){
tmp->next = head;
return tmp;
}else{
Stu *pre, *cur = head;
while(cur && ((cur->score > tmp->score) || (cur->score==tmp->score))){
pre = cur;
cur = cur->next;
}
if(cur == NULL){
pre->next = tmp;
}else{
tmp->next = cur;
pre->next = tmp;
}
return head;
}
}

int main()
{
printf("**** Pro-1 ****\n");

printf("please input the number of students to be sorted by scores \n");
int num_of_stu = 0;
scanf("%d",&num_of_stu);

printf("please input 0 or 1, 0 means down and 1 up \n");
int up_or_down = -1;
scanf("%d",&up_or_down);

if(!(num_of_stu>0 && (up_or_down==0 || up_or_down==1))){
printf("invalid input\n");
return -1;
}

Stu *head = (Stu *)malloc(sizeof(Stu));
head->next = NULL;
head->score = 0;
//        node_print(head);

for(int i=1;i<=num_of_stu;i++){
Stu *tmp_node = (Stu *)malloc(sizeof(Stu));
//            printf("input num %d
a84d
name:\n",i);
//            scanf("%s",tmp_node->name);
//            printf("input num %d score:\n",i);
//            scanf("%d",&tmp_node->score);
printf("please input num%d's name and score\n",i);
scanf("%s %d",tmp_node->name,&tmp_node->score);
tmp_node->next = NULL;

if(1==up_or_down){
head = up(head,tmp_node);
}
else if(0==up_or_down){
head = down(head,tmp_node);
}
}

Stu *pre, *cur = head;
printf("SORTED list:\n");
while(cur){
printf("%s ====> %d\n",cur->name,cur->score);
pre = cur;
cur = cur->next;
free(pre);
pre = NULL;
}

return 0;
}

CODE BLOCKS上运行结果