关于#c语言#的问题，请各位专家解答！

img

img

这两个有什么区别
qwertyuioplkkjhgfxvhjgujxfjgthhdyy

第一个s的类型是根据a和b的类型来指定
第二个s的类型指定为float类型

  • 这篇博客: 学生信息管理系统（双向链表）（C语言）中的 登录密码是：qwerty 部分也许能够解决你的问题, 你可以仔细阅读以下内容或跳转源博客中阅读:

  • 在这里插入图片描述
    在这里插入图片描述

    在这里插入图片描述

    #define _CRT_SECURE_NO_WARNINGS 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct student
{
	int Student_number;
	char Student_name[10];
	int Student_grade;
	char Student_major[10];
	int Student_score_1;
	int Student_score_2;
	int Student_score_3;
	int Student_average_score;
	int Student_Sum_average;
	struct student* pre;
	struct student* next;
}Student;
typedef struct student_message
{
	int Student_Num;
	Student* p;
	Student* head;
}Student_Message;

void save_file(Student_Message* Stu);
void show_student(Student_Message* Stu);
void add_student(Student_Message* Stu);
Student* search_student(Student_Message* Stu);
int delete_student(Student_Message* Stu);
int change_student(Student_Message* Stu);
void Search_Student(Student_Message* Stu);
void clean_student();
void land();
void keydowm(Student_Message* Stu);
void sort(Student_Message*Stu);
void readstudent(Student_Message*Stu);

void save_file(Student_Message*Stu)
{
	Student* temp = Stu->head;
	FILE* fp= NULL;
	fp = fopen("学生信息.txt", "w+");
	if (fp == NULL)
		return;
	//fprintf(fp, "学生学号   学生年级     学生年级   学生专业    学生成绩\n");
	fprintf(fp, "%d ", Stu->Student_Num);
	while (temp->next)
	{
		fprintf(fp, "%d\t%d\t%s\t%s\t%d\t", temp->Student_number, temp->Student_grade,
			temp->Student_name, temp->Student_major, temp->Student_score_1);
		temp = temp->next;
	}
	fprintf(fp, "%d\t%d\t%s\t%s\t%d", temp->Student_number, temp->Student_grade,
		temp->Student_name, temp->Student_major, temp->Student_score_1);
	fclose(fp);
}
void show_student(Student_Message* Stu)
{
	Student* temp = Stu->head;
	while (temp->next)
	{
		printf("学生学号     学生年级     学生姓名      "
			"学生专业    学生的成绩    \n%d\t%d\t%s\t%s\t%d\n", temp->Student_number, temp->Student_grade,
			temp->Student_name, temp->Student_major, temp->Student_score_1);
		temp = temp->next;
	}
	printf("学生学号     学生年级     学生姓名      "
		"学生专业    学生的成绩    \n%d\t%d\t%s\t%s\t%d\n", temp->Student_number, temp->Student_grade,
		temp->Student_name, temp->Student_major, temp->Student_score_1);
}
void add_student(Student_Message*Stu)
{
	Student* temp = NULL;
	Student* new_temp = (Student*)malloc(sizeof(Student));
	
	printf("请输入学生学号          请输入学生年级                请输入学生的成绩 "
		" 请输入学生姓名            请输入学生专业                \n");
	scanf("%d%d%d%s%s", &(new_temp->Student_number),&(new_temp->Student_grade),
		&(new_temp->Student_score_1),(new_temp->Student_name), (new_temp->Student_major));
	/*printf("请输入学生学号    ,请输入学生年级   , 请输入学生姓名    , "
		"请输入学生专业   ,请输入学生的成绩    \n%d\t%d\t%s\t%s\t%d\n", new_temp->Student_number, new_temp->Student_grade,
		new_temp->Student_name, new_temp->Student_major, new_temp->Student_score_1);*/
	if (Stu->head == NULL)
	{
		Stu->head = new_temp;
		Stu->head->pre = NULL;
		Stu->head->next = NULL;
		/*Stu->p = Stu->head->next;
		Stu->p->pre = Stu->head;*/
		Stu->p = Stu->head;
	}
	else
	{
		//temp = new_temp;
		new_temp->pre = Stu->p;
		Stu->p->next = new_temp;
		Stu->p = Stu->p->next;
		Stu->p->next = NULL;
	}
	Stu->Student_Num++;
	show_student(Stu);
}
Student* search_student(Student_Message*Stu)
{
	char name[12];
	Student* temp=Stu->head;
	printf("请输入你要查询学生的姓名\n");
	scanf("%s", name);
	while (temp->next != NULL && strcmp(name, temp->Student_name) != 0)
		temp = temp->next;
	if (strcmp(name, temp->Student_name) == 0)
		return temp;
	else
		return NULL;
}
int delete_student(Student_Message*Stu)
{
	Student*temp=search_student(Stu);
	if (temp == NULL)
	{
		printf("删除节点失败\n");
		return 0;
	}
	else
	{
		if(temp->pre!=NULL)
			temp->pre->next = temp->next;
		free(temp);
		printf("删除节点成功\n");
		return 1;
	}
	show_student(Stu);
	Stu->Student_Num--;
}
int change_student(Student_Message* Stu)
{
	Student* temp = search_student(Stu);
	if (temp == NULL)
	{
		printf("修改失败\n");
	}
	else
	{
		printf("请输入学生学号，请输入学生年级,请输入学生姓名,"
			"请输入学生专业,请输入学生的成绩\n");
		scanf("%d%d%s%s%d", &temp->Student_number, &temp->Student_grade,
			temp->Student_name, temp->Student_major, &temp->Student_score_1);
		printf("修改成功\n");
	}
	show_student(Stu);
}
void Search_Student(Student_Message*Stu)
{
	Student *temp=search_student(Stu);
	printf("请输入学生学号    ,请输入学生年级   , 请输入学生姓名    , "
		"请输入学生专业   ,请输入学生的成绩    \n%d\t%d\t%s\t%s\t%d\n", temp->Student_number, temp->Student_grade,
		temp->Student_name, temp->Student_major, temp->Student_score_1);
}
void clean_student()
{

}
void land()
{
	int n = 0,flag=1;
	printf("-----------------请输入你的密码，你有三次机会----------------\n");
	char password[7] = {'q','w','e','r','t','y','\0'};
	char userpassword[7];
	while (n < 3)
	{
		printf("----------------请输入你的密码，你现在还有%d机会--------------\n",3-n);
		scanf("%s", userpassword);
		printf("%d",strcmp(userpassword, password));
		if (strcmp(userpassword, password) == 0)
			return;
		n++;
	}
	exit(0);
}
void sort(Student_Message* Stu)
{
	Student temp;
	Student* Phead = Stu->head;
	Student* Ptail = Phead;
	while (Phead)
	{
		Ptail = Phead;
		while (Ptail)
		{
			if(Phead->Student_score_1>=Ptail->Student_score_1)
				Ptail = Ptail->next;
			else
			{
				temp.Student_score_1 = Phead->Student_score_1;
				temp.Student_grade = Phead->Student_grade;
				strcpy( temp.Student_major ,Phead->Student_major);
				strcpy(temp.Student_name, Phead->Student_name);
				temp.Student_number = Phead->Student_number;

				Phead->Student_score_1 = Ptail->Student_score_1;
				Phead->Student_grade = Ptail->Student_grade;
				Phead->Student_number = Ptail->Student_number;
				strcpy(Phead->Student_major, Ptail->Student_major);
				strcpy(Phead->Student_name, Ptail->Student_name);

				Ptail->Student_score_1 = temp.Student_score_1;
				Ptail->Student_grade = temp.Student_grade;
				Ptail->Student_number = temp.Student_number;
				strcpy(Ptail->Student_major, temp.Student_major);
				strcpy(Ptail->Student_name,temp.Student_name );

				Ptail = Ptail->next;
			}	
		}
		Phead = Phead->next;
	}
}
void readstudent(Student_Message*Stu)
{
	Student* new_temp=(Student*)malloc(sizeof(Student));
	FILE* fp = fopen("学生信息.txt", "r");
	if (fp == NULL)
	{
		printf("读取文件失败\n");
		return;
	}
	fscanf(fp,"%d ", &Stu->Student_Num);
	fscanf(fp, "%d\t%d\t%s\t%s\t%d\t", &new_temp->Student_number, &new_temp->Student_grade,
		new_temp->Student_name, new_temp->Student_major, &new_temp->Student_score_1);
	if (Stu->head == NULL)
	{
		Stu->head = new_temp;
		Stu->head->pre = NULL;
		Stu->head->next = NULL;
		/*Stu->p = Stu->head->next;
		Stu->p->pre = Stu->head;*/
		Stu->p = Stu->head;
	}
	for (int i = 0; i < Stu->Student_Num - 1; i++)
	{
		Student* temp=(Student*)malloc(sizeof(Student));
		fscanf(fp, "%d\t%d\t%s\t%s\t%d\t", &temp->Student_number, &temp->Student_grade,
			temp->Student_name, temp->Student_major, &temp->Student_score_1);
		temp->pre = Stu->p;
		Stu->p->next = temp;
		Stu->p = Stu->p->next;
		Stu->p->next = NULL;
	}
	fclose(fp);
}
void keydowm(Student_Message*Stu)
{
	int choice;
	printf("------------------------学生信息管理系统---------------------------\n\n");
	printf("1.添加学生信息                      2.查找学生信息\n");
	printf("3.修改学生信息                      4.删除学生信息\n");
	printf("5.展示学生信息                      6.退出\n");
	printf("7.保存到txt文件                     8.依照学生成绩排序\n");
	printf("请在键盘敲下你的命令\n");
	printf("--------------------------------------------------------------------\n");
	scanf("%d", &choice);
	getchar();
	switch (choice)
	{
	case 1:
		add_student(Stu); break;
	case 2:
		Search_Student(Stu);
		break;
	case 3:
		change_student(Stu);
		break;
	case 4:
		delete_student(Stu);
		break;
	case 5:
		show_student(Stu);
		break;
	case 6:
		exit(0);
		break;
	case 7:
		save_file(Stu);
		break;
	case 8:
		sort(Stu);	
		break;
	default:
		break;
	}
	system("pause");
	system("cls");
}

int main()
{
	Student_Message Stu;
	Stu.Student_Num = 0;
	Stu.head = NULL;
	Stu.p = Stu.head;
	land();
	system("cls");
	readstudent(&Stu);
	while (1)
	{
		keydowm(&Stu);
	}
	return 0;
}
  • 以下回答由chatgpt基于相关博客总结生成:

    对不起，您的问题不太清楚，请提供更明确的信息和问题的上下文，以便我更好地帮助您解决问题。如果您需要关于C语言方面的问题，请详细说明您遇到的问题或困难，并提供相关的代码和错误提示。感谢您的合作！

如果是C语言, 如果s和sum的类型是float, 那么结果不同
整数相除还是整数, 舍去余数.
如 5/2 == 2
强制转换为float, 则以浮点方式运算
如 5.0/2 == 2.5