我正在修改一个小程序，我已经成功地将这个小程序变成了一个更大的程序，但我仍然需要两个函数。
我正在帮助我的一个朋友。
#include <stdio.h>
#define CAPACITY 100
/* User commands */
#define ADD 'a'
#define FIND 'f'
#define LIST 'l'
#define QUIT 'q'
#define NAME_LEN 80
#define NUMBER_LEN 40
/* In memory representation of an entry in the phonebook. */
typedef struct {
char name[ NAME_LEN ];
char number[ NUMBER_LEN ];
} phone_record;
/* Procedures in phonebook.c */
char get_command( void );
phone_record *get_record( void );
void add_record( phone_record *new_record );
void list_phonebook( void );
int find_name( char *name );
int num_entries; // Number of entries currently in the phone book
phone_record **phonebook; // Where the names are stored
int main( int argc, char **argv ) {
char ch;
char name[ NAME_LEN ];
char confirm[ 10 ];
phone_record *rec;
int loc;
// Create an empty phonebook
phonebook = (phone_record **)malloc( sizeof( phone_record *) * CAPACITY );
num_entries = 0;
// Read commands until the user gets tired
while ( ( ch = get_command() ) != QUIT ) {
switch( ch ) {
case ADD:
// Get new info
rec = get_record();
add_record( rec );
break;
case FIND:
// Name to find
printf( "Name: " );
scanf( "%s", name );
// Look for the name
if ( ( loc = find_name( name ) ) != -1 ) {
printf( "Number: %s\n", phonebook[ loc ]->number );
}
else {
printf( "That name is not in the phonebook\n" );
}
break;
case LIST:
// List the phonebook
list_phonebook();
break;
}
}
}
/*
* Read and return a command from the keyboard.
*/
char get_command() {
char line[ 80 ];
do {
// Get input
printf( "pb> " );
// scanf returns -1 when it encoutners EOF - pretend we saw quit
if ( scanf( "%s", line ) == -1 ) {
line[ 0 ] = QUIT;
printf( "\n" ); // Add new line so terminal looks nice
}
// Verify input (lightly)
switch( line[ 0 ] ) {
case ADD:
case FIND:
case LIST:
case QUIT:
break;
default:
printf( "Unrecognized command\n" );
line[ 0 ] = 0;
}
} while ( line[ 0 ] == 0 );
return line[ 0 ];
}
/*
* Add a new record to the phonebook.
*/
void add_record( phone_record *new_record ) {
int cur;
// Make sure there is room
if ( num_entries == CAPACITY ) {
printf( "Sorry phonebook is full\n" );
}
else {
// Insertion sort. Start at bottom and copy elements down one until
// you find the first one less than what we are adding or we hit the
// top of the phonebook
for ( cur = num_entries;
cur > 0 && strcmp( phonebook[ cur - 1 ]->name, new_record->name ) > 0;
cur = cur - 1 ) {
phonebook[ cur ] = phonebook[ cur - 1 ];
}
// Add the entry in the open slot
phonebook[ cur ] = new_record;
num_entries = num_entries + 1;
}
}
/*
* List the entries in the phonebook.
*/
void list_phonebook() {
int i;
if ( num_entries != 0 ) {
printf( "Name\t\tNumber\n" );
printf( "----\t\t------\n" );
for ( i = 0; i < num_entries; i = i + 1 ) {
printf( "%s\t\t%s\n", phonebook[ i ]->name, phonebook[ i ]->number );
}
}
else {
printf( "There are no entries in the phonebook\n" );
}
}
/*
* Find a name in the phonebook. -1 means it is not there.
*/
int find_name( char *name ) {
int pos = -1;
int i;
for ( i = 0; pos == -1 && i < num_entries; i = i + 1 ) {
if ( strcmp( name, phonebook[ i ]->name ) == 0 ) pos = i;
}
return pos;
}
/*
* Read and return a phone record from the keyboard.
*/
phone_record *get_record() {
phone_record *rec;
char *name;
char *number;
// Allocate storage for the phone record. Since we want the record
// to live after the function returns we need to use malloc
rec = (phone_record *)malloc( sizeof( phone_record ) );
// Get the data
printf( "Name: " );
scanf( "%s", rec->name );
printf( "Phone: " );
scanf( "%s", rec->number );
return rec;
}
在电话簿阵列中找到匹配名称的find_name()函数是：
int find_name( char *name ) {
int pos = -1;
int i;
for ( i = 0; pos == -1 && i < num_entries; i = i + 1 ) {
if ( strcmp( name, phonebook[ i ]->name ) == 0 ) pos = i;
}
return pos;
}
它只返回一个显示电话簿匹配元素位置的整数：
if ( ( loc = find_name( name ) ) != -1 ) {
printf( "Number: %s\n", phonebook[ loc ]->number );
}
我认为方法find_name应该返回一个数组，但我不知道如何实现它。
答案 0 :(得分：1)
使用负数（-1）返回整数数组可能最简单，以指示整数列表的结尾。
因此，您的功能将被修改为类似以下内容。我实际上没有编译这个，所以你可能需要解决一些问题。
int find_name( char *name, int *iList, int nListSize ) {
int pos = -1;
int i;
int j;
for ( j = i = 0; i < num_entries; i = i + 1 ) {
if ( strcmp( name, phonebook[ i ]->name ) == 0 ) {
if (j + 1 < nListSize)
iList[j++] = i;
}
}
iList[j] = -1; // indicate the end of the list
if (j < nListSize) pos = j; // return the number of items in the list
return pos;
}
您需要修改使用此函数创建整数数组的方式，并将数组与最大数组条目一起传递。然后检查返回值以确定找到了多少（如果有）匹配。
如果找到的匹配项数多于可用的数组元素，则该函数返回-1。
修改
在case FIND:中你会做一个类似于下面的输出循环。我再次没有进行编译或测试，但这是概念。如果此示例中有超过100个匹配的名称，那么您确实遇到了问题，因此您需要考虑如何处理这种可能性：
// Look for the name
{
int aList[100]; // just a large array and hope no more than this matching entries
if ( ( loc = find_name( name, aList, 100 ) ) > 0 ) {
int iLoop = 0;
// loop through the list to print out the matching entries.
for (iLoop= 0; aList[iLoop] >= 0; iLoop++) {
printf( "Number: %s\n", phonebook[ aList[iLoop] ]->number );
}
}
else {
printf( "That name is not in the phonebook or too many matches\n" );
}
}
修改
您也可以考虑使用稍微不同的方法来创建使用迭代器类型方法的find_name()。我们的想法是拥有一个充当电话簿迭代器的变量。如果有匹配的名称，则迭代器变量返回指向匹配数据的指针。
我再次编译或测试过，所以可能需要你做一些工作。
由于需要更新迭代器结构，我们需要传递一个指向迭代器结构的指针，以便在处理电话簿数组时更新它。
int find_name( char *name, phonebookitera *pItera ) {
int pos = -1;
for (; pItera->pos < num_entries; pItera->pos++ ) {
if ( strcmp( name, phonebook[ pItera->pos ]->name ) == 0 ) {
// copy the matching pointers to our iterator
pItera->name = phonebook[ pItera->pos ]->name;
pItera->number = phonebook[ pItera->pos ]->number;
// we will return the matching position in phonebook though not necessary
pos = pItera->pos;
pItera->pos++; // increment to the following element
return pos;
}
}
return pos;
}
此函数将用于以下代码中。
{
phonebookitera myItera = {0};
// iterate through the list to print out the matching entries.
if (find_name (name, &myItera) >= 0) {
do {
printf( "Number: %s\n", myItera.number );
} while (find_name (name, &myItera) >= 0);
} else {
printf( "That name is not in the phonebook\n" );
}
}
您可以将phonebookitera定义为：
typedef struct {
int pos;
char *name;
char *number;
} phonebookitera;
答案 1 :(得分：0)
使用NAMES作为过滤器获取数字列表的最简单方法是：
find_by_surname(surname);＆lt; ---在CASE FIND
和查找名称功能：
void find_name( char *name ) {
int i;
if ( num_entries != 0 ) {
printf( "Name\t\tNumber\n" );
printf( "----\t\t------\n" );
for ( i = 0; i < num_entries; i = i + 1 ) {
if ( strcmp( name, phonebook[ i ]->name ) == 0 )
printf( "%s\t\t%s\n", phonebook[ i ]->name, phonebook[ i ]->number );
}
}
else {
printf( "There are no entries in the phonebook\n" );
}
}