Generating an array of integers - c

Question

I got a problem in generating an array of integers. the program fills hundreds of cells of the array with numbers like -32429173 instead of 3 cells with numbers from 0 to 3 (for example). Maybe the problem is in the wrong way of allocating memory? Here is the wrong part of the code. Thx for the help in advance.
int* generate()
{
int maxnumb;
int i;
scanf_s("%d",&size); //size of an array
scanf_s("%d",&maxnumb); //asks for maxnumb to fill the array with random numbers from 0 to maxnumb
int* array=(int*)calloc(size,sizeof(int));
for (i=0;i<size;i++)
array[i] = rand() % maxnumb + 1;
return array;
}
Here is the full code
#define _CRT_SECURE_NO_WARNINGS
#include<stdlib.h>
#include<stdio.h>
int size;
void swap(int* elem1,int* elem2) //swap elements
{
int temp;
temp=*elem1;
*elem1=*elem2;
*elem2=temp;
}
void bublesort(int* array,int size) //bublesort
{
for (int j=1;j<size-1;++j)
{
for (int i=0;i<size-j;++i)
{
if ((array[i])>(array[i+1]))
swap(&array[i],&array[i+1]);
}
}
}
int* enterHand() //handle entering
{
int i;
scanf_s("%d",&size);
int* array=(int*)calloc(size,sizeof(int));
for (i=0;i<size;i++)
{
scanf_s("%d",&array[i]);
}
return array;
}
int* enterFile() //entering from the file
{
int i;
int singlenumb;
FILE* foo;
errno_t err;
err=fopen_s(&foo,"input.txt","r");
if( err == 0 )
{
printf( "The file 'input.txt' was opened\n" );
}
else
{
printf( "The file 'input.txt' was not opened\n" );
}
while (!feof(foo))
{
fscanf_s(foo, "%d", &singlenumb);
size++;
}
size-=1;
int* array=(int*)calloc(size,sizeof(int));
rewind(foo);
i=0;
while (i!=size)
{
fscanf_s(foo, "%d", &array[i]);
i++;
}
fclose(foo);
return array;
}
int* generate()
{
int maxnumb;
int i;
scanf_s("%d",&size); //size of an array
scanf_s("%d",&maxnumb); //asks for maxnumb to fill the array with random numbers from 0 to maxnumb
int* array=(int*)calloc(size,sizeof(int));
for (i=0;i<size;i++)
array[i] = rand() % maxnumb + 1;
return array;
}
void putsFile(int* array, int size)
{
int i=0;
int k;
FILE* fooo;
fopen_s(&fooo,"output.txt","w");
while (i!=size)
{
for (k=0; k<10; k++)
{
fprintf(fooo,"%d ", array[i]);
i++;
}
fprintf(fooo,"\n");
}
fclose(fooo);
}
void printArray(int* array, int size)
{
int i=0;
int k;
while (i!=size)
{
for (k=0; k<10; k++)
{
printf("%d ", array[i]);
i++;
}
printf("\n");
}
}
int main()
{
int choice;
int* pntr;
printf("choose a type of filling an array\n1 = handle filling\n2 = filling from the file\n3 = generating\nenter the number...\n");
scanf("%d", &choice);
switch (choice)
{
case 1: {pntr=enterHand();} break;
case 2: {pntr=enterFile();} break;
case 3: {pntr=generate();} break;
default: {pntr=NULL;}
}
bublesort(pntr,size);
printf("choose a type of typing an array\n1 = console\n2 = file\nenter the number...\n");
scanf("%d", choice);
switch (choice)
{
case 1: {printArray(pntr, size);} break;
case 2: {putsFile(pntr, size);} break;
default: {printf("you entered the wrong number");}
}
return 0;
}

Answer 1

I think you should initialize your maxnumb

Answer 2

First, here is a simpler approach for filling an array.
int randomGenerator(int min, int max);
int main(void)
{
int array[100]//or any size
for(i=0;i<sizeof(array)/sizeof(array[0]);i++)
{
array[i]=randomGenerator(1,3);//will issue only 1, 2 or three (as you requested)
} //change min and max for wider range
return 0;
}
int randomGenerator(int min, int max) //set the range of desired numbers in array
{
int random=0, trying=0;
trying = 1;
while(trying)
{
srand(clock());
random = (rand()/32767.0)*(max+1);
(random >= min) ? (trying = 0) : (trying = 1);
}
return random;
}
There are also some things you can do to make this non-repeating, i.e. so you won't get two Ace of Spades. But for now, you have much bigger issues...
Your code, as is has too many issues to build. If you post a small, buildable section, with the specific problem, it can be better addressed.

Answer 3

The printArray() and putsFile() may print outside array size.
int* enterFile() does not set size to 0 before determining number of int in the file, thus using a potentially unexpected non-zero size.
[Edit] Well size is implicitly set to 0 being in the global uninitialized space. Still, recommend explicitly setting to 0 in enterFile().
#if 0
// The value of size is dependent on program history or uninitialized.
while (!feof(foo)) {
fscanf_s(foo, "%d", &singlenumb);
size++;
}
size-=1;
#else
size = 0; // Reset size to 0
while (1 == fscanf_s(foo, "%d", &singlenumb)) {
size++;
}
#endif
Suggest:
void printArray(int* array, int size) {
// Also in void putsFile(int* array, int size)
int i=0;
while (i < size) {
int k;
for (k=0; k<10; k++) {
printf("%d ", array[i]);
i++;
// Add
if (i >= size) break;
}
printf("\n");
}
}