Segmentation fault

**langesh** · Mar 25 '07, 06:57 AM

the problem for Segmentation fault is u r accessing some memory but memory is not allocated.

see where u r access with out allocating memory.

or use GDB to find where its giving Segmentation fault....

Originally posted by codeveloper

I have written a function where I have to use merge sort.
My program is due Monday. Please, if anyone can help me out. Here is the code, plus I have declared a struct which I am using.

typedef struct restaurant
{
char name[STRING];
int code;
char food;
int entree;
float high_cost;
float low_cost;
float distance;
char children;
char senior;
int age;
int open1;
int close1;
int open2;
int close2;
char days_open[8];
int waitime;
float avg_cost;
char family;
} REST;

/*************** *************** *************** *************** *************** ****
FUNCTION NAME : sort_by_food
INPUTS : array of sturcts rest, int first and last
RETURNS : none
PURPOSE : sorts the data by the type of food
*************** *************** *************** *************** *************** ****/

void sort_by_food( REST rest[], int first, int last )
{
int middle;

middle = ( first + last ) / 2;
if( first < last )
{
sort_by_food( rest, first, middle );
sort_by_food( rest, middle + 1, last );
merge_food( rest, first, middle, middle + 1, last );
}
}

/*************** *************** *************** *************** *************** ****
FUNCTION NAME : merge_food
INPUTS : array of sturcts rest, int first1, last1, first2, last2
RETURNS : none
PURPOSE : sorts the data by the type of food
*************** *************** *************** *************** *************** ****/

void merge_food( REST rest[], int first1, int last1, int first2, int last2 )
{
REST temp[SIZE];

int i, i1, i2; // index, index 1, index 2
int num, fi; // num, find index

i = 0;
i1 = first1;
i2 = first2;
num = last1 - first1 + last2 - first2 + 2;
while( (i1 <= last1) && (i2 <= last2) )
{
if( rest[i1].food < rest[i2].food)
{
strcpy(temp[i].name, rest[i1].name);
temp[i].code = rest[i1].code;
temp[i].food = rest[i1].food;
temp[i].entree = rest[i1].entree;
temp[i].high_cost = rest[i1].high_cost;
temp[i].low_cost = rest[i1].low_cost;
temp[i].distance = rest[i1].distance;
temp[i].children = rest[i1].children;
temp[i].senior = rest[i1].senior;
temp[i].age = rest[i1].age;
temp[i].open1 = rest[i1].open1;
temp[i].close1 = rest[i1].close1;
temp[i].open2 = rest[i1].open2;
temp[i].close2 = rest[i1].close2;
strcpy(temp[i].days_open, rest[i1].days_open);
temp[i].waitime = rest[i1].waitime;
temp[i].avg_cost = rest[i1].avg_cost;
temp[i].family = rest[i1].family;
i++;
i1++;
}
else
{
strcpy(temp[i].name, rest[i2].name);
temp[i].code = rest[i2].code;
temp[i].food = rest[i2].food;
temp[i].entree = rest[i2].entree;
temp[i].high_cost = rest[i2].high_cost;
temp[i].low_cost = rest[i2].low_cost;
temp[i].distance = rest[i2].distance;
temp[i].children = rest[i2].children;
temp[i].senior = rest[i2].senior;
temp[i].age = rest[i2].age;
temp[i].open1 = rest[i2].open1;
temp[i].close1 = rest[i2].close1;
temp[i].open2 = rest[i2].open2;
temp[i].close2 = rest[i2].close2;
strcpy(temp[i].days_open, rest[i2].days_open);
temp[i].waitime = rest[i2].waitime;
temp[i].avg_cost = rest[i2].avg_cost;
temp[i].family = rest[i2].family;
i++;
i2++;
}
}

if( i1 > last1 )
{
while( i2 <= last2 )
{
strcpy(temp[i].name, rest[i2].name);
temp[i].code = rest[i2].code;
temp[i].food = rest[i2].food;
temp[i].entree = rest[i2].entree;
temp[i].high_cost = rest[i2].high_cost;
temp[i].low_cost = rest[i2].low_cost;
temp[i].distance = rest[i2].distance;
temp[i].children = rest[i2].children;
temp[i].senior = rest[i2].senior;
temp[i].age = rest[i2].age;
temp[i].open1 = rest[i2].open1;
temp[i].close1 = rest[i2].close1;
temp[i].open2 = rest[i2].open2;
temp[i].close2 = rest[i2].close2;
strcpy(temp[i].days_open, rest[i2].days_open);
temp[i].waitime = rest[i2].waitime;
temp[i].avg_cost = rest[i2].avg_cost;
temp[i].family = rest[i2].family;
i++;
i2++;
}
}
else
{
while( i1 <= last1 )
{
strcpy(temp[i].name, rest[i1].name);
temp[i].code = rest[i1].code;
temp[i].food = rest[i1].food;
temp[i].entree = rest[i1].entree;
temp[i].high_cost = rest[i1].high_cost;
temp[i].low_cost = rest[i1].low_cost;
temp[i].distance = rest[i1].distance;
temp[i].children = rest[i1].children;
temp[i].senior = rest[i1].senior;
temp[i].age = rest[i1].age;
temp[i].open1 = rest[i1].open1;
temp[i].close1 = rest[i1].close1;
temp[i].open2 = rest[i1].open2;
temp[i].close2 = rest[i1].close2;
strcpy(temp[i].days_open, rest[i1].days_open);
temp[i].waitime = rest[i1].waitime;
temp[i].avg_cost = rest[i1].avg_cost;
temp[i].family = rest[i1].family;
i++;
i1++;
}
}

fi = 0;
while( fi <= num - 1 )
{
strcpy(rest[first1].name, temp[fi].name);
rest[first1].code = temp[fi].code;
rest[first1].food = temp[fi].food;
rest[first1].entree = temp[fi].entree;
rest[first1].high_cost = temp[fi].high_cost;
rest[first1].low_cost = temp[fi].low_cost;
rest[first1].distance = temp[fi].distance;
rest[first1].children = temp[fi].children;
rest[first1].senior = temp[fi].senior;
rest[first1].age = temp[fi].age;
rest[first1].open1 = temp[fi].open1;
rest[first1].close1 = temp[fi].close1;
rest[first1].open2 = temp[fi].open2;
rest[first1].close2 = temp[fi].close2;
strcpy(rest[first1].days_open, temp[fi].days_open);
rest[first1].waitime = temp[fi].waitime;
rest[first1].avg_cost = temp[fi].avg_cost;
rest[first1].family = temp[fi].family;
first1++;
fi++;
}
}

**horace1** · Mar 25 '07, 08:01 AM

you are probably exceeding the bounds of an array - either use a debugger or put print statements in to try to localise the problem, e.g.

Code:

void sort_by_food( REST rest[], int first, int last )
{
int middle;

middle = ( first + last ) / 2;
if( first < last )
{
printf("1 first %d last %d  midel %d\n",first, last, middle);
sort_by_food( rest, first, middle );
printf("2 first %d last %d  midel %d\n",first, last, middle);
sort_by_food( rest, middle + 1, last );
printf("3 first %d last %d  midel %d\n",first, last, middle);
merge_food( rest, first, middle, middle + 1, last );
}
}

when you know which function the error is on put print statements in that etc

recursive functions such as sort_by_food() can also run out of stack space - how big is SIZE ?

Segmentation fault

Segmentation fault

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