C Language - Student achievement management system

Preface

I'm reviewing recently C Language and data structure , So use pure C Language single chain table to write a performance management system to practice .

Implemented function

The main interface of the system is as follows ：

As shown in the interface , The main functions are as follows ：

• Increase record
• Delete record
• Query log
• Modify the record
• Sort
• Sum and average

It's easy to write , But these basic functions have been realized , I hope it can play a role in attracting jade .

The system has a lot of room to optimize , For example, you can use the clear screen function system(“cls”); （ Its header file is stdlib.h） To get a better experience .

Add student information

The head inserting method is realized 、 Tail interpolation and global traversal .

// Add student  
bool add_student(stu *L)
{
    
	int number;// Student number 
	char name[10];// full name 
	int Chinese;// Chinese achievement 
	int maths;// Math scores 
	int English;// English scores 
	
	printf(" Please enter the following information in turn ： Student number 、 full name 、 Chinese achievement 、 Math scores 、 English scores ( Press enter to enter the next item after each entry )\n");
	scanf("%d",&number);
	scanf("%s",name);
	scanf("%d",&Chinese);
	scanf("%d",&maths);
	scanf("%d",&English);
	
	// Apply for a new memory space 
	stu *p;	// The pointer P Point to the currently scanned node 
	p = L;		//L Point to the head node , The head node is the second node 0 Nodes ( No data )
	stu *s = (stu *)malloc(sizeof(stu));
	
	// Assign a value to the new node  
	s->number = number;
	for(int i=0;i<sizeof(name);i++) // Array element assignment cannot make array equal to array directly  
		s->name[i] = name[i];
	s->Chinese = Chinese;
	s->maths = maths;
	s->English = English;
	
	// The change of the pointer  
	s->next = p->next;
	p->next = s;
	
	return true;
}

// Show all information , Global traversal 
void show_all(stu *L)
{
    
	printf(" All student information is as follows ：\n");
	printf(" Student number \t full name \t Chinese achievement \t Math scores \t English scores \t\n");
	stu *p;
	p = L->next;//p Point to the head node 

	while(p!=NULL) 
	{
    
		printf("%4d %s %3d %3d %3d\n",p->number,p->name,p->Chinese,p->maths,p->English);
		p = p->next;
	}
	
} 

The above is realized according to the head insertion method , The tail interpolation Ideas ： It is similar to the head inserting method ,p First equals the head pointer , Let it move all the way back , Until it points to the end , To insert nodes .

// Add student  
bool add_student(stu *L)
{
    
	// The first interpolation 
	int number;// Student number 
	char name[10];// full name 
	int Chinese;// Chinese achievement 
	int maths;// Math scores 
	int English;// English scores 
	
	printf(" Please enter the following information in turn ： Student number 、 full name 、 Chinese achievement 、 Math scores 、 English scores ( Press enter to enter the next item after each entry )\n");
	scanf("%d",&number);
	scanf("%s",name);
	scanf("%d",&Chinese);
	scanf("%d",&maths);
	scanf("%d",&English);
	
	// Apply for a new memory space 
	stu *p;	// The pointer P Point to the currently scanned node 
	p = L;		//L Point to the head node , The head node is the second node 0 Nodes ( No data )
	stu *s = (stu *)malloc(sizeof(stu));
	
	// Assign a value to the new node  
	s->number = number;
	for(int i=0;i<sizeof(name);i++) // Array element assignment cannot make array equal to array directly  
		s->name[i] = name[i];
	s->Chinese = Chinese;
	s->maths = maths;
	s->English = English;
	
	//------------ The tail interpolation ------------// 
    // The tail interpolation method mainly includes this while loop 
	while(p->next!=NULL)
	{
    
		p = p->next;
	}
	s->next = p->next;
	p->next = s;
	//------------ The tail interpolation ------------// 
	
	return true;
}

According to the student number

The idea of querying by student number is very simple , Just traverse with a pointer , Then compare whether the student number of the data pointed to by the pointer is consistent with the student number you query , If consistent, output , If not, continue the cycle .

// According to the student number 
bool search_num(stu *L,int num)
{
    
	stu *p;
	p = L->next;
	
	while(p!=NULL) 
	{
    
		if(p->number == num) 
		{
    
			printf("%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",p->number,p->name,p->Chinese,p->maths,p->English);
			return true;
		}
		p = p->next;
	}
	return false;
}

Delete student records according to student id

Deleting is a little different from querying . To delete, first find the node data you want to delete , But because this is a single linked list , So you need to find the previous node of the node to be deleted , Change the pointer of the previous node directly to the next node of the node you want to delete , Then release the node you want to delete .

// Delete... According to student number  
bool del_student(stu *L,int num)
{
    
	stu *p;
	p = L;// Give Way p Start from scratch  
	
	while(p->next!=NULL) 
	{
    
		stu *q = p->next; // q Point to the deleted node 
		if(q->number == num) //p If you want to delete the next node data  
		{
    
			printf(" The node data you deleted is ：\n%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",q->number,q->name,q->Chinese,q->maths,q->English);
			p->next = q->next;// Delete 
			free(q); 
			return true;
		}
		p = p->next;
	}
	return false;
}

Query and modify the information according to the student number

It's easy to modify . You need to query before modifying , After finding the data , Make an assignment of the data .

// Query and modify the information according to the student number  
bool verify_num(stu *L,int num)
{
    
	stu *p;
	p = L->next;
	
	while(p!=NULL) 
	{
    
		if(p->number == num) 
		{
    
			printf(" The information you want to modify is ：\n Student number \t full name \t Chinese achievement \t Math scores \t English scores \t\n");
			printf("%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",p->number,p->name,p->Chinese,p->maths,p->English);
				
			int number;// Student number 
			char name[10];// full name 
			int Chinese;// Chinese achievement 
			int maths;// Math scores 
			int English;// English scores 
			
			printf(" Please re-enter the following information ： Student number 、 full name 、 Chinese achievement 、 Math scores 、 English scores ( Press enter to enter the next item after each entry )\n");
			scanf("%d",&number);
			scanf("%s",name);
			scanf("%d",&Chinese);
			scanf("%d",&maths);
			scanf("%d",&English);
			
			// Assign a value to this node  
			p->number = number;
			for(int i=0;i<sizeof(name);i++) // Array element assignment cannot make array equal to array directly  
				p->name[i] = name[i];
			p->Chinese = Chinese;
			p->maths = maths;
			p->English = English;
			return true;
		}
		p = p->next;
	}
	return false;
}

According to the Chinese scores from high to low

Sorting this is a little more complicated , Because there are many steps . It should be noted that , Sorting cannot change the structure of the original linked list , So I did an operation to take out the linked list data and put it into an array , Then sort the array .

// Sort according to Chinese scores  
bool sort_Chinese(stu *L)
{
    
	int numbers = 0;// Count the number of records first  
	stu *p;
	p = L->next;
	
	while(p!=NULL) 
	{
    
		numbers++;
		p = p->next;
	}
	printf(" A total of %d Student records ！\n",numbers);
	stu data[numbers]; // Put all the data into this array , Perform statistical operations on this array  
	
	p = L->next;// Give Way p Point back to the beginning  

		for(int i=0;i<numbers;i++) 
		{
    
			if(p!=NULL) 
			{
    
				data[i].number = p->number;
				for(int j=0;j<sizeof(p->name);j++) // Array element assignment cannot make array equal to array directly  
					data[i].name[j] = p->name[j];
				data[i].Chinese = p->Chinese;
				data[i].maths = p->maths;
				data[i].English = p->English;
				
				p = p->next;
			}
		}
	
	int temp_num;// Temporary student number 
	char temp_name[10];
	int temp_Chinese;
	int temp_maths;
	int temp_English;
	 
	// Sort according to Chinese scores 
	for(int i=0;i<numbers-1;i++)
	{
    
		for(int j=0;j<numbers-1-i;j++)
		{
    
			if(data[j].Chinese<data[j+1].Chinese)
			{
    
				// Exchange student numbers 
				temp_num = data[j+1].number;
				data[j+1].number = data[j].number;
				data[j].number = temp_num;
				// Exchange names 
				for(int k=0;k<sizeof(data[0].name);k++) // Array element assignment cannot make array equal to array directly  
				{
    
					temp_name[k] = data[j+1].name[k];
					data[j+1].name[k] = data[j].name[k];
					data[j].name[k] = temp_name[k];
				}
				// Exchange Chinese scores  
				temp_Chinese = data[j+1].Chinese;
				data[j+1].Chinese = data[j].Chinese;
				data[j].Chinese = temp_Chinese;
				// Exchange math grades 
				temp_maths = data[j+1].maths;
				data[j+1].maths = data[j].maths;
				data[j].maths = temp_maths;
				// Exchange English scores 
				temp_English = data[j+1].English;
				data[j+1].English = data[j].English;
				data[j].English = temp_English;
			}
		}
	}
	
	// Output the sorted result 
	printf(" The result of sorting is as follows ( Chinese scores are ranked from high to low )：\n Student number \t full name \t Chinese achievement \t Math scores \t English scores \t\n"); 
	
	for(int i=0;i<numbers;i++)
	{
    
		printf("%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",data[i].number,data[i].name,data[i].Chinese,data[i].maths,data[i].English);
	}
} 

All the code

#include<stdio.h>
#include<stdlib.h>
#include<stdbool.h> // according to C99 standard ,C Language use bool Type needs to add this header file  
 

// Structure declaration part 
typedef struct Student
{
    
	int number;// Student number 
	char name[10];// full name 
	int Chinese;// Chinese achievement 
	int maths;// Math scores 
	int English;// English scores 
	struct Student *next; // Pointer to the next element  
}stu,*stuList; 

/*-------- Function declaration part --------*/ 
void MainMenu();// The main menu , Used for display  
bool add_student(stu *L);// Add student records  
void show_all(stu *L);// Show all student information 
bool del_student(stu *L,int num);// Delete student information according to student number  
bool search_num(stu *L,int num);// According to the student number 
bool verify_num(stu *L,int num);// Query and modify the information according to the student number  
bool sort_Chinese(stu *L);// Sort according to Chinese scores  

bool InitList(stu *L);// Student list initialization  
bool Empty(stu *L);// The linked list is empty  
 
/*-------- Function declaration part --------*/


int main()
{
    
	int ch;// Selected sequence number 
	int ch_num;// Query according to student number 、 Delete 、 Modification and other operations  
	
	
	stu L;

	if(InitList(&L))
		printf(" The linked list was initialized successfully ！\n");// Prompt information , If not needed, delete , But you must initialize the linked list first ！ 
	else
		printf(" Linked list initialization failed ！\n");
	
	while(1)
	{
    
		MainMenu();// Display main interface  
		
		printf("\n Please enter the sequence number of the operation you want to perform ：");
		scanf("%d",&ch);
		switch(ch)
		{
    
			case 0: printf(" Thank you for using ！");	exit(0);	break;
			case 1: add_student(&L);  break;
			case 2: printf(" Please enter the student number of the student you want to delete ：");
					scanf("%d",&ch_num);
					if(del_student(&L,ch_num))
						printf(" Delete successful ！\n");	
					else
					    printf(" Delete failed , No such record ！\n");	
					break;
			case 3: printf(" Please enter the student number of the student you want to modify ：");
					scanf("%d",&ch_num);
					if(verify_num(&L,ch_num))
						printf(" Modification successful ！\n");	
					else
					    printf(" Modification failed , No such record ！\n");	
					break;
			case 4:    
					printf(" Please enter the student number you want to query ：");
					scanf("%d",&ch_num);
					if(search_num(&L,ch_num))
						printf(" The query is successful ！\n");	
					else
					    printf(" The query fails , No such record ！\n");	
					break;
			case 5:
					sort_Chinese(&L);		break;
			case 6: show_all(&L);  break;
			default:	printf(" The operation sequence number you entered is incorrect , Please re-enter ！\n");
		}
	}
	return 0;
}

// The main menu , Show  
void MainMenu()
{
    
	printf("\n\n\n");
	printf("\t ********** Student achievement management system ***********\n"); 
	printf("\t ------- 0. Exit the system  \n\n");
	printf("\t ------- 1. Enter student scores \n\n");
	printf("\t ------- 2. Delete record \n\n");
	printf("\t ------- 3. Modify student information \n\n");
	printf("\t ------- 4. Search for student information \n\n");
	printf("\t ------- 5. Sort by Chinese score \n\n");
	printf("\t ------- 6. Show all student information \n\n");
	printf("\t *************************************\n");
}

// Initialize single chain table （ Leading node ）
bool InitList(stu *L)
{
    
	L = (stu *)malloc(sizeof(stu));	// Assign a head node 
	if (L==NULL)	// Out of memory , Allocation failed 
		return false;	
	L->next = NULL;	// There is no node after the head node 
	return true;
}


// Add student  
bool add_student(stu *L)
{
    
	
	int number;// Student number 
	char name[10];// full name 
	int Chinese;// Chinese achievement 
	int maths;// Math scores 
	int English;// English scores 
	
	printf(" Please enter the following information in turn ： Student number 、 full name 、 Chinese achievement 、 Math scores 、 English scores ( Press enter to enter the next item after each entry )\n");
	scanf("%d",&number);
	scanf("%s",name);
	scanf("%d",&Chinese);
	scanf("%d",&maths);
	scanf("%d",&English);
	
	// Apply for a new memory space 
	stu *p;	// The pointer P Point to the currently scanned node 
	p = L;		//L Point to the head node , The head node is the second node 0 Nodes ( No data )
	stu *s = (stu *)malloc(sizeof(stu));
	
	// Assign a value to the new node  
	s->number = number;
	for(int i=0;i<sizeof(name);i++) // Array element assignment cannot make array equal to array directly  
		s->name[i] = name[i];
	s->Chinese = Chinese;
	s->maths = maths;
	s->English = English;
	
	//------------ The first interpolation ------------// 
	// The change of the pointer  
// s->next = p->next;
// p->next = s;
	//------------ The first interpolation ------------//
	
	//------------ The tail interpolation ------------// 
	// notes ： The tail interpolation method mainly includes this while loop , That is, first let the pointer point to the end of the linked list, and then insert  
	while(p->next!=NULL)
	{
    
		p = p->next;
	}
	s->next = p->next;
	p->next = s;
	//------------ The tail interpolation ------------// 
	
	
	return true;
}

// Show all information  
void show_all(stu *L)
{
    
	printf(" All student information is as follows ：\n");
	printf(" Student number \t full name \t Chinese achievement \t Math scores \t English scores \t\n");
	stu *p;
	p = L->next;
	
	while(p!=NULL) 
	{
    
		printf("%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",p->number,p->name,p->Chinese,p->maths,p->English);
		p = p->next;
	}
} 


// According to the student number 
bool search_num(stu *L,int num)
{
    
	stu *p;
	p = L->next;
	
	while(p!=NULL) 
	{
    
		if(p->number == num) 
		{
    
			printf("%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",p->number,p->name,p->Chinese,p->maths,p->English);
			return true;
		}
		p = p->next;
	}
	return false;
}

// Delete... According to student number  
bool del_student(stu *L,int num)
{
    
	stu *p;
	p = L;// Give Way p Start from scratch  
	
	while(p->next!=NULL) 
	{
    
		stu *q = p->next; // q Point to the deleted node 
		if(q->number == num) //p If you want to delete the next node data  
		{
    
			printf(" The node data you deleted is ：\n%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",q->number,q->name,q->Chinese,q->maths,q->English);
			p->next = q->next;// Delete 
			free(q); 
			return true;
		}
		p = p->next;
	}
	return false;
}

// Query and modify the information according to the student number  
bool verify_num(stu *L,int num)
{
    
	stu *p;
	p = L->next;
	
	while(p!=NULL) 
	{
    
		if(p->number == num) 
		{
    
			printf(" The information you want to modify is ：\n Student number \t full name \t Chinese achievement \t Math scores \t English scores \t\n");
			printf("%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",p->number,p->name,p->Chinese,p->maths,p->English);
			
			int number;// Student number 
			char name[10];// full name 
			int Chinese;// Chinese achievement 
			int maths;// Math scores 
			int English;// English scores 
			
			printf(" Please re-enter the following information ： Student number 、 full name 、 Chinese achievement 、 Math scores 、 English scores ( Press enter to enter the next item after each entry )\n");
			scanf("%d",&number);
			scanf("%s",name);
			scanf("%d",&Chinese);
			scanf("%d",&maths);
			scanf("%d",&English);
			
			// Assign a value to this node  
			p->number = number;
			for(int i=0;i<sizeof(name);i++) // Array element assignment cannot make array equal to array directly  
				p->name[i] = name[i];
			p->Chinese = Chinese;
			p->maths = maths;
			p->English = English;
			return true;
		}
		p = p->next;
	}
	return false;
}

// Sort according to Chinese scores  
bool sort_Chinese(stu *L)
{
    
	int numbers = 0;// Count the number of records first  
	stu *p;
	p = L->next;
	
	while(p!=NULL) 
	{
    
		numbers++;
		p = p->next;
	}
	printf(" A total of %d Student records ！\n",numbers);
	stu data[numbers]; // Put all the data into this array , Perform statistical operations on this array  
	
	p = L->next;// Give Way p Point back to the beginning  

		for(int i=0;i<numbers;i++) 
		{
    
			if(p!=NULL) 
			{
    
				data[i].number = p->number;
				for(int j=0;j<sizeof(p->name);j++) // Array element assignment cannot make array equal to array directly  
					data[i].name[j] = p->name[j];
				data[i].Chinese = p->Chinese;
				data[i].maths = p->maths;
				data[i].English = p->English;
				
				p = p->next;
			}
		}
		
	
	
// printf(" After saving into the array ：\n"); // You can check whether the saved results are correct  
// for(int i=0;i<numbers;i++)
// {
    
// printf("%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",data[i].number,data[i].name,data[i].Chinese,data[i].maths,data[i].English);
// }
	
	int temp_num;// Temporary student number 
	char temp_name[10];
	int temp_Chinese;
	int temp_maths;
	int temp_English;
	 
	// Sort according to Chinese scores 
	for(int i=0;i<numbers-1;i++)
	{
    
		for(int j=0;j<numbers-1-i;j++)
		{
    
			if(data[j].Chinese<data[j+1].Chinese)
			{
    
				// Exchange student numbers 
				temp_num = data[j+1].number;
				data[j+1].number = data[j].number;
				data[j].number = temp_num;
				// Exchange names 
				for(int k=0;k<sizeof(data[0].name);k++) // Array element assignment cannot make array equal to array directly  
				{
    
					temp_name[k] = data[j+1].name[k];
					data[j+1].name[k] = data[j].name[k];
					data[j].name[k] = temp_name[k];
				}
				// Exchange Chinese scores  
				temp_Chinese = data[j+1].Chinese;
				data[j+1].Chinese = data[j].Chinese;
				data[j].Chinese = temp_Chinese;
				// Exchange math grades 
				temp_maths = data[j+1].maths;
				data[j+1].maths = data[j].maths;
				data[j].maths = temp_maths;
				// Exchange English scores 
				temp_English = data[j+1].English;
				data[j+1].English = data[j].English;
				data[j].English = temp_English;
			}
		}
	}
	
	// Output the sorted result 
	printf(" The result of sorting is as follows ( Chinese scores are ranked from high to low )：\n Student number \t full name \t Chinese achievement \t Math scores \t English scores \t\n"); 
	
	for(int i=0;i<numbers;i++)
	{
    
		printf("%-4d\t%s\t%-3d\t\t%-3d\t\t%-3d\n",data[i].number,data[i].name,data[i].Chinese,data[i].maths,data[i].English);
	}
} 

System function test