我正在尝试使用链表创建一个主题先决条件检查器。我知道如何将单个数据插入节点。
我的问题是如何将多个数据插入一个节点?我找到了一个非常适合我的任务的好例子。但问题是我不太懂C。任何人都可以帮助解释以下void add()
功能吗?我想将该add
功能用于我的作业。
#include <stdio.h>
#include <conio.h>
#include <malloc.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
struct node
{
char data [ 20 ];
char m [ 5 ] [ 20 ];
int mcount;
struct node * link;
};
struct node * dic [ 26 ];
void add ( char * );
int search ( char * );
void show( );
void deldic( );
void main( )
{
char word [ 20 ] , ch;
int i;
clrscr( );
while ( 1 )
{
clrscr( );
printf ( "\n\t\tDictionary\n" );
printf ( "\n\t\t1.Add Word.\n" );
printf ( "\t\t2.Search Word.\n" );
printf ( "\t\t3.Show Dictionary.\n" );
printf ( "\t\t0.Exit." );
printf ( "\n\n\t\tYour Choice ");
scanf ( "%d", &ch );
switch ( ch )
{
case 1 :
printf ( "\nEnter any word : " );
fflush ( stdin );
gets ( word );
add ( word );
break;
case 2 :
printf ( "\nEnter the word to search : " );
fflush ( stdin );
gets ( word );
i = search ( word );
if ( ! i )
printf ( "Word does not exists." );
getch( );
break;
case 3 :
show( );
getch( );
break;
case 0 :
deldic( );
exit ( 0 );
default :
printf ( "\nWrong Choice" );
}
}
}
void add ( char * str )
{
int i, j = toupper ( str [ 0 ] ) - 65;
struct node * r, * temp = dic [ j ], * q;
char mean [ 5 ] [ 20 ], ch = 'y';
i = search ( str );
if ( i )
{
printf ( "\nWord already exists." );
getch( );
return;
}
q = ( struct node * ) malloc ( sizeof ( struct node ) );
strcpy ( q -> data, str );
q -> link = NULL;
for ( i = 0; tolower ( ch ) == 'y' && i < 5; i++ )
{
fflush ( stdin );
printf ( "\n\nEnter the meaning(s) : " );
gets ( mean [ i ] );
strcpy ( q -> m [ i ] , mean [ i ] );
if ( i != 4 )
printf ( "\nAdd more meanings (y/n) " );
else
printf ( "You cannot enter more than 5 meanings." );
fflush ( stdin );
ch = getche( );
}
q -> mcount = i;
if ( dic [ j ] == NULL || strcmp ( dic [ j ] -> data, str ) > 0 )
{
r = dic [ j ];
dic [ j ] = q;
q -> link = r;
return;
}
else
{
while ( temp != NULL )
{
if ( ( strcmp ( temp -> data, str ) < 0 ) && ( ( strcmp ( temp -> link -> data, str ) > 0 ) ||
temp -> link == NULL ) )
{
q -> link = temp -> link;
temp -> link = q;
return;
}
temp = temp -> link;
}
}
}
这是我到目前为止的任务
#include <iostream>
#include <string>
#include <iomanip>
using namespace std;
struct subjectlist
{
string subject;
string prereq;
subjectlist *next;
};
subjectlist *start_prt=NULL;
subjectlist *current;
int option=0;
int main ()
{
int x;
string subject;
cout << "1. Add subject" << endl;
cout << "2. Search prerequisite" << endl;
cout << "3. Delete subject" << endl;
cout << "4.Show subjects" << endl;
cout << "5. Save to file" << endl;
cout << "6. Load from file" << endl;
cout << "0. Exit" << endl;
cin >> x;
switch (x)
{
case 1:
cout<<"Input subject"<<endl;
cin >> subject;
add(subject);
break;
case 2:
cout<<"Input subject to be checked"<<endl;
break;
case 3:
cout<<"Delete a subject"<<endl;
break;
case 4:
cout<<"Show Subjects"<<endl;
break;
case 5:
cout<<"Save to File"<<endl;
break;
case 6:
cout<<"Load from file"<<endl;
break;
case 0:
cout<<"exit"<<endl;
break;
default: cout <<"Invalid selection, please try again."<<endl;
}
}
void add ()
{
}