- C Programming The Code The Code Below Doesn T Work As It S Supposed To Fix The Functions So That They Work As The C 1 (29.68 KiB) Viewed 63 times
/*
The code below doesn’t work as it’s supposed to. Fix the
functions so that
they work as the comments describe and don’t produce compiler
errors or warnings,
nor valgrind errors or memory leaks. The main function has no
problems, and
it cannot be changed. The structures are also defined correctly,
and no includes
are missing. In general, the logic of the code is correct.
The program handles map data, more specifically public
transportation stops. The program
saves them in a Map structure, that holds a location name, a
TransportStop linked list.
The TransportStop structure holds the data for a single Transit
stop, and stores
the name and type of the TransportStop, as well as the location
(a latitude-longitude pair)
of the TransportStop.
There are six mistakes in the program, each of them clearly
visible either in
the compiler errors/warnings or valgrind output. Note that there
might be more
than one error/warning per mistake as a single mistake can
create many problems at once.
There is one mistake in the createStop function.
There are two mistakes in the createStops function.
There is one mistake in the createMap function.
There is one mistake in the printStopInfo function.
There is one mistake in the freeMemory function.
*/
//
----------------------------------------------------------------------
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
// Transit stop structure holds the location
// as latitude-longitude pair, types as an enum value
// and the identifier and the name of the stop as string
typedef struct transportStop TransportStop;
/**
* \brief Public transportation stop types are defined
using a set of enum values
*
*/
typedef enum stopType { ALEPA_BIKE, BUS, METRO, TRAM }
StopType;
/**
* \brief Transport stop structure that is specified by
location, identifier, type and
* name.
*
*/
struct transportStop {
double location[2]; //!< The location as
a latitude-longitude pair
char identifier[6]; //!< The identifier
of point of interest as a string
StopType type; //!< The
transportation stop type
char* name;
//!< The name of the step
TransportStop* next; //!< The next stop
};
/**
* \brief A map structure for public tranport stop, which
is composed of
* a linked-list of transport stops and the name of the
map
*
*/
typedef struct map {
TransportStop* stops; //!< A linked-list of
transportation stops
char* locationName; //!< The name of the
map
} Map;
// Function createStop creates a linked-list member with the
given data.
/**
* \brief Create a public transportation stop linked-list
member
*
* \param name The name of the transport stop
* \param identifier The stop identifier
* \param type The type of the stop
* \param location A pair of doubles that have the
longitude-latitude of the transportation stops
*
* \return A dynamically allocated and initialized
transport stop linked-list member
*/
TransportStop* createStop(const char* name,
const char* identifier,
StopType type,
double location[2]) {
// Allocate memory for TransportStop
TransportStop* stop =
malloc(sizeof(TransportStop));
// Allocate memory for the stop name and copy it
to the structure
stop->name = malloc(strlen(name) + 1);
strcpy(stop->name, name);
// Store the id
strncpy(stop->identifier, identifier, 5);
stop->identifier[6] = '\0';
// Store the type
stop->type = type;
// Store the location as lat-lon
stop->location[0] = location[0];
stop->location[1] = location[1];
// Set the next pointer
stop->next = NULL;
return stop;
}
/**
* \brief Create a linked-list of public transportation
stops
*
* \param stopNames An array of public transportation stop
names
* \param ids An array of public transportation stop
identifiers
* \param types An array of public transportation stop
types
* \param locations An array of pairs of doubles that have
the longitude-latitude pairs for each stop
* \param stopCount The number of public transportation
stops
* \return A dynamically allocated and initialized
linked-list of transport stops
*/
TransportStop createStops(char** stopNames,
char** ids,
StopType* types,
double locations[][2],
int stopCount) {
TransportStop* stop =
createStop(stopNames[0], ids[0],
types[0], locations[0]);
TransportStop* start = stop;
// Go through all the given data and store it in
the linked list
for(int i = 1; i < stopCount; i++) {
stop = createStop(stopNames,
ids, types, locations);
stop = stop->next;
}
return start; // Return the created stops
}
/**
* \brief Create a Map object from the arguments
*
* \param locationName The name of the map location
* \param stopNames An array of public transportation stop
names
* \param ids An array of public transportation stop
identifiers
* \param types An array of public transportation stop
types
* \param locations An array of pairs of doubles that have
the longitude-latitude pairs for each stop
* \param stopCount The number of public transportation
stops
*
* \return A dynamically allocated and initialized map
object
*/
Map* createMap(char* locationName,
char**
stopNames,
char**
stopIds,
StopType*
types,
double
locations[][2],
int
stopCount) {
// Allocate memory for the Map structure
Map* map = malloc(sizeof(Map));
// Store the location name
map->locationName =
malloc(strlen(locationName));
strcpy(map->locationName, locationName);
// Store the public transportation stop
information
map->stops = createStops(stopNames, stopIds,
types, locations, stopCount);
return map;
}
/**
* \brief Returns a human-readable string for the public
transportation stop type
*
* \param type The stop type
* \return The human readable string of the stop type
*/
const char* getTypeName(StopType type) {
switch (type)
{
case ALEPA_BIKE:
return "bike";
case BUS:
return "bus";
case METRO:
return "metro";
case TRAM:
return "tram";
default:
return "invalid type";
}
}
/**
* \brief Prints the content of a Map object
*
* \details This function prints the content of a Map
object in the following
* format:
*
* <place name> has
the following public transportation stops:
* Stop <name>, ID
<identifier> at (latitude, longitude) of type
<type>.
* ...
*
* \param map The map object to be printed
*/
void printStopInfo(Map* map) {
printf("%s has the following public transportation
stops:\n",
map->locationName);
// Loop through the stops and print their info
for(TransportStop* curr = map->stops; curr;
curr = curr->next) {
printf("Stop %s, ID %s at (%f, %f)
is of type %s.\n",
curr->name,
curr->identifier,
curr->location[0],
curr->location[1],
getTypeName(curr.type));
}
}
/**
* \brief Frees the dynamically allocated memory for a map
object
*
* \param map The object to be freed
*/
void freeMemory(Map* map) {
// Free linked list memory
for(TransportStop* curr = map->stops; curr !=
NULL;) {
TransportStop* del = curr;
curr = curr->next;
free(del->name);
}
free(map->locationName);
free(map);
}
/**
* \brief Main function of the program
*
* \return Returns 0
*/
int main() {
// Original data for the public transportation
stops:
// Names
char* names[] = {"Aalto-yliopiston
metroasema",
"Aalto-yliopisto (M)",
"Aalto-yliopisto (M), Korkeakoulunaukio",
"Aalto-yliopisto (M), Tietotie",
"Jämeräntaival",
"Teekkarikylä",
"Otaranta"};
char* identifiers[] =
{"OTA", "E2230", "541", "539",
"547", "E2228", "null"};
StopType types[] =
{METRO, BUS, ALEPA_BIKE, ALEPA_BIKE,
ALEPA_BIKE, BUS, TRAM};
// Transit stop location, a latitude-longitude
pair
double locations[][2] = {{60.18448, 24.82358},
{60.18369, 24.82812},
{60.18431, 24.82666},
{60.18498, 24.82013},
{60.18812, 24.83505},
{60.18743, 24.83388},
{60.18021, 24.83468}};
// Create a map structure based on the data
Map* map = createMap("Otaniemi", names,
identifiers, types, locations, 7);
// Print map tiles information
printStopInfo(map);
// Free the reserved memory
freeMemory(map);
return 0;
}
The code in the provided template doesn't work as it is supposed to. Fix the functions so that they work as the comments describe and they don't produce compiler warnings/errors or valgrind errors. You can make the following assumptions: • The main function has no problems. • The structures are defined correctly. • No includes are missing. • In general, the logic of the code is correct. The program handles map data, more specifically public transportation stops. The program saves them in a map structure, that holds a location name and a linked list of Transportstop structures. The Transportstop structure holds the data for a single public transportation stop, and stores the name and type of the stop, as well as the location (a latitude-longitude pair) of the stop. There are six mistakes in the program: • There is one mistake in the createstop function. • There are two mistakes in the createstops function. • There is one mistake in the createMap function. • There is one mistake in the printstopInfo function. • There is one mistake in the freeMemory function.