Deleting an element from an array of pointers to structs - c

I have an array of pointers to structs, and what I want to do is delete an element and shift all the rest to fill the gap. I have written a function which seems to work, however valgrind complains about 'invalid read/write of size 8' so now I'm wondering if what I did was incorrect.
Here's the code:
for (int i = (numOfApartments-1); i >= 0; i--) {
if (apartmentIsIdentical(apartment, apartmentArray[i]->apartment)) {
apartmentDestroy(apartmentArray[i]->apartment);
free(apartmentArray[i]);
shiftApartments(apartmentArray, i, numOfApartments);
numOfApartments--;
return 1;
}
}
static void shiftApartments(ApartmentInfo* array, int startIndex, int endIndex) {
for (int i = startIndex; i < endIndex; i++) {
swapApartments(&array[i], &array[i + 1]);
}
}
static void swapApartments(ApartmentInfo* apartment1, ApartmentInfo* apartment2) {
ApartmentInfo temp = *apartment1;
*apartment1 = *apartment2;
*apartment2 = temp;
}
My question is mainly whether the free(apartmentArray[i]) is correct. The way I see it, it should leave an empty slot which I just move to the end of the array and place something else there later. However the error of 'invalid read/write of size 8' made me wonder whether freeing apartmentArray[i] actually make the slot inaccessible..? Why does it say I can't write to it?
Thanks!

since you freed apartmentArray[i], you cant swap the values, just assign the pointer in shiftApartments
try to replace
swapApartments(&array[i], &array[i + 1]);
with
array[i] = array[i+1];

memmove() is your friend here. Memmove handles the cases of overlapping moves, and can avoid an explicit loop. The only difficulty is to get the sizes right!
(I use an array of pointers to character, but this is essentially not different from pointers to struct. Except that you should not attempt to free() them ;-)
#include <stdio.h>
#include <string.h>
int main(void)
{
char *array[] = { "one", "two", "three", "four"
, "five", "six", "seven", "eight" };
/* using an array of pointers to string literals
** , so free() should not be used here ...
*/
#define SHOULDFREE(s) fprintf(stderr,"Should free %s\n", s)
unsigned size = 8;
unsigned idx,top;
for (top=idx=size; idx-- > 0; ) {
/* only delete words that start with 't' */
if (*array[idx] != 't') continue;
SHOULDFREE(array[idx]);
top--;
if (idx >=top) continue;
fprintf(stderr,"about to move %u (%s) (%u elements) one place down\n"
, idx+1, array[idx+1], top-idx);
memmove( &array[idx], &array[idx+1], (top-idx) * sizeof array[0] );
}
for (idx=0; idx < top; idx++) {
printf("[%u]: %s\n", idx, array[idx] );
}
return 0;
}
And, of course the
memmove( &array[idx], &array[idx+1], (top-idx) * sizeof array[0] );
could be replaced by:
memmove( array+idx, array+idx+1, (top-idx) * sizeof array[0] );

Related

last number in a function array

I want to write a function where I have a given array and number N. The last occurrence of this number I want to return address. If said number cannot be found I want to use a NULL-pointer
Start of the code I've made:
int main(void) {
int n = 3;
int ary[6] = { 1,3,7,8,3,9 };
for (int i = 0; i <= 6; i++) {
if (ary[i] == 3) {
printf("%u\n", ary[i]);
}
}
return 0;
}
result in command prompt:
3
3
The biggest trouble I'm having is:
it prints all occurrences, but not the last occurrence as I want
I haven't used pointers much, so I don't understand how to use the NULL-pointer
I see many minor problems in your program:
If you want to make a function, make a function so your parameters and return types are explicit, instead of coding directly in the main.
C arrays, like in most languages, start the indexing at 0 so if there are N element the first has index 0, then the second has 1, etc... So the very last element (the Nth) has index N-1, so in your for loops, always have condition "i < size", not "i <= size" or ( "i <= size-1" if y'r a weirdo)
If you want to act only on the last occurence of something, don't act on every. Just save every new occurence to the same variable and then, when you're sure it was the last, act on it.
A final version of the function you describe would be:
int* lastOccurence(int n, int* arr, int size){
int* pos = NULL;
for(int i = 0; i < size; i++){
if(arr[i] == n){
pos = &arr[i]; //Should be equal to arr + i*sizeof(int)
}
}
return pos;
}
int main(void){
int n = 3;
int ary[6] = { 1,3,7,8,3,9 };
printf("%p\n", lastOccurence(3, ary, 6);
return 0;
}
Then I'll add that the NULL pointer is just 0, I mean there is literally the line "#define NULL 0" inside the runtime headers. It is just a convention that the memory address 0 doesn't exist and we use NULL instead of 0 for clarity, but it's exactly the same.
Bugs:
i <= 6 accesses the array out of bounds, change to i < 6.
printf("%u\n", ary[i]); prints the value, not the index.
You don't actually compare the value against n but against a hard-coded 3.
I think that you are looking for something like this:
#include <stdio.h>
int main(void)
{
int n = 3;
int ary[6] = { 1,3,7,8,3,9 };
int* last_index = NULL;
for (int i = 0; i < 6; i++) {
if (ary[i] == n) {
last_index = &ary[i];
}
}
if(last_index == NULL) {
printf("Number not found\n");
}
else {
printf("Last index: %d\n", (int)(last_index - ary));
}
return 0;
}
The pointer last_index points at the last found item, if any. By subtracting the array's base address last_index - ary we do pointer arithmetic and get the array item.
The cast to int is necessary to avoid a quirk where subtracting pointers in C actually gives the result in a large integer type called ptrdiff_t - beginners need not worry about that one, so just cast.
First of all, you will read from out of array range, since your array last element is 5, and you read up to 6, which can lead in segmentation faults. #Ludin is right saying that you should change
for (int i = 0; i <= 6; i++) // reads from 0 to 6 range! It is roughly equal to for (int i = 0; i == 6; i++)
to:
for (int i = 0; i < 6; i++) // reads from 0 to 5
The last occurrence of this number I want to return as address.
You are printing only value of 3, not address. To do so, you need to use & operator.
If said number cannot be found I want to use a NULL-pointer
I don't understand, where do you want to return nullpointer? Main function can't return nullpointer, it is contradictory to its definition. To do so, you need to place it in separate function, and then return NULL.
If you want to return last occurence, then I would iterate from the end of this array:
for (int i = 5; i > -1; i--) {
if (ary[i] == 3) {
printf("place in array: %u\n", i); // to print iterator
printf("place in memory: %p\n", &(ary[i])); // to print pointer
break; // if you want to print only last occurence in array and don't read ruther
}
else if (i == 0) {
printf("None occurences found");
}
}
If you want to return an address you need yo use a function instead of writing code in main
As you want to return the address of the last occurence, you should iterate the array from last element towards the first element instead of iterating from first towards last elements.
Below are 2 different implementations of such a function.
#include <stdio.h>
#include <assert.h>
int* f(int n, size_t sz, int a[])
{
assert(sz > 0 && a != NULL);
// Iterate the array from last element towards first element
int* p = a + sz;
do
{
--p;
if (*p == n) return p;
} while(p != a);
return NULL;
}
int* g(int n, size_t sz, int a[])
{
assert(sz > 0 && a != NULL);
// Iterate the array from last element towards first element
size_t i = sz;
do
{
--i;
if (a[i] == n) return &a[i];
} while (i > 0);
return NULL;
}
int main(void)
{
int n = 3;
int ary[] = { 1,3,7,8,3,9 };
size_t elements = sizeof ary / sizeof ary[0];
int* p;
p = g(n, elements, ary); // or p = f(n, elements, ary);
if (p != NULL)
{
printf("Found at address %p - value %d\n", (void*)p, *p);
}
else
{
printf("Not found. The function returned %p\n", (void*)p);
}
return 0;
}
Working on the specified requirements in your question (i.e. a function that searches for the number and returns the address of its last occurrence, or NULL), the code below gives one way of fulfilling those. The comments included are intended to be self-explanatory.
#include <stdio.h>
// Note that an array, passed as an argument, is converted to a pointer (to the
// first element). We can change this in our function, because that pointer is
// passed BY VALUE (i.e. it's a copy), so it won't change the original
int* FindLast(int* arr, size_t length, int find)
{
int* answer = NULL; // The result pointer: set to NULL to start off with
for (size_t i = 0; i < length; ++i) { // Note the use of < rather than <=
if (*arr == find) {
answer = arr; // Found, so set our pointer to the ADDRESS of this element
// Note that, if multiple occurrences exist, the LAST one will be the answer
}
++arr; // Move on to the next element's address
}
return answer;
}
int main(void)
{
int num = 3; // Number to find
int ary[6] = { 1,3,7,8,3,9 }; // array to search
size_t arrlen = sizeof(ary) / sizeof(ary[0]); // Classic way to get length of an array
int* result = FindLast(ary, arrlen, num); // Call the function!
if (result == NULL) { // No match was found ...
printf("No match was found in the array!\n");
}
else {
printf("The address of the last match found is %p.\n", (void*)result); // Show the address
printf("The element at that address is: %d\n", *result); // Just for a verification/check!
}
return 0;
}
Lots of answers so far. All very good answers, too, so I won't repeat the same commentary about array bounds, etc.
I will, however, take a different approach and state, "I want to use a NULL-pointer" is a silly prerequisite for this task serving only to muddle and complicate a very simple problem. "I want to use ..." is chopping off your nose to spite your face.
The KISS principle is to "Keep It Simple, St....!!" Those who will read/modify your code will appreciate your efforts far more than admiring you for making wrong decisions that makes their day worse.
Arrays are easy to conceive of in terms of indexing to reach each element. If you want to train in the use of pointers and NULL pointers, I suggest you explore "linked lists" and/or "binary trees". Those data structures are founded on the utility of pointers.
int main( void ) {
const int n = 3, ary[] = { 1, 3, 7, 8, 3, 9 };
size_t sz = sizeof ary/sizeof ary[0];
// search for the LAST match by starting at the end, not the beginning.
while( sz-- )
if( ary[ sz ] == n ) {
printf( "ary[ %sz ] = %d\n", sz, n );
return 0;
}
puts( "not found" );
return 1; // failed to find it.
}
Consider that the array to be searched is many megabytes. To find the LAST match, it makes sense to start at the tail, not the head of the array.
Simple...

Try to split string but got messy substrings

I try to split one string to 3-gram strings. But turns out that the resulting substrings were always messy. The length and char ** input... are needed, since I will use them as args later for python calling the funxtion.
This is the function I wrote.
struct strArrIntArr getSearchArr(char* input, int length) {
struct strArrIntArr nameIndArr;
// flag of same bit
int same;
// flag/index of identical strings
int flag = 0;
// how many identical strings
int num = 0;
// array of split strings
char** nameArr = (char **)malloc(sizeof(char *) * (length - 2));
if ( nameArr == NULL ) exit(0);
// numbers of every split string
int* valueArr = (int* )malloc(sizeof(int) * (length-2));
if ( valueArr == NULL ) exit(0);
// loop length of search string -2 times (3-gram)
for(int i = 0; i<length-2; i++){
if(flag==0){
nameArr[i - num] = (char *)malloc(sizeof(char) * 3);
if ( nameArr[i - num] == NULL ) exit(0);
printf("----i------------%d------\n", i);
printf("----i-num--------%d------\n", i-num);
}
flag = 0;
// compare splitting string with existing split strings,
// if a string exists, it would not be stored
for(int k=0; k<i-num; k++){
same = 0;
for(int j=0; j<3; j++){
if(input[i + j] == nameArr[k][j]){
same ++;
}
}
// identical strings found, if all the three bits are the same
if(same == 3){
flag = k;
num++;
break;
}
}
// if the current split string doesn't exist yet
// put current split string to array
if(flag == 0){
for(int j=0; j<3; j++){
nameArr[i-num][j] = input[i + j];
valueArr[i-num] = 1;
}
}else{
valueArr[flag]++;
}
printf("-----string----%s\n", nameArr[i-num]);
}
// number of N-gram strings
nameIndArr.length = length- 2- num;
// array of N-gram strings
nameIndArr.charArr = nameArr;
nameIndArr.intArr = valueArr;
return nameIndArr;
}
To call the function:
int main(int argc, const char * argv[]) {
int length = 30;
char* input = (char *)malloc(sizeof(char) * length);
input = "googleapis.com.wncln.wncln.org";
// split the search string into N-gram strings
// and count the numbers of every split string
struct strArrIntArr nameIndArr = getSearchArr(input, length);
}
Below is the result. The strings from 17 are messy.
----i------------0------
----i-num--------0------
-----string----goo
----i------------1------
----i-num--------1------
-----string----oog
----i------------2------
----i-num--------2------
-----string----ogl
----i------------3------
----i-num--------3------
-----string----gle
----i------------4------
----i-num--------4------
-----string----lea
----i------------5------
----i-num--------5------
-----string----eap
----i------------6------
----i-num--------6------
-----string----api
----i------------7------
----i-num--------7------
-----string----pis
----i------------8------
----i-num--------8------
-----string----is.
----i------------9------
----i-num--------9------
-----string----s.c
----i------------10------
----i-num--------10------
-----string----.co
----i------------11------
----i-num--------11------
-----string----com
----i------------12------
----i-num--------12------
-----string----om.
----i------------13------
----i-num--------13------
-----string----m.w
----i------------14------
----i-num--------14------
-----string----.wn
----i------------15------
----i-num--------15------
-----string----wnc
---i------------16------
----i-num--------16------
-----string----ncl
----i------------17------
----i-num--------17------
-----string----clnsole
----i------------18------
----i-num--------18------
-----string----ln.=C:
----i------------19------
----i-num--------19------
-----string----n.wgram 馻绚s
----i------------20------
----i-num--------20------
-----string----n.wgram 馻绚s
-----string----n.wgram 馻绚s
-----string----n.wgram 馻绚s
-----string----n.wgram 馻绚s
-----string----n.wgram 馻绚s
-----string----n.oiles(騛窑=
----i------------26------
----i-num--------21------
-----string----.orSModu鯽蓼t
----i------------27------
----i-num--------22------
-----string----org
under win10, codeblocks 17.12, gcc 8.1.0
You are making life complicated for you in several places:
Don't count backwards: Instead of making num the count of duplicates, make it the count of unique trigraphs.
Scope variable definitions in functions as closely as possible. You have several uninitialized variables. You have declared them at the start of the function, but you need them only in local blocks.
Initialize as soon as you allocate. In your code, you use a flag to determine whather to create a new string. The code to allocate he string and to initialize it are in different blocks. Those blocks have the same flag as condition, but the flag is updated in between. This could lead to asynchronities, even to bugs when you try to initialize memory that wasn't allocated.
It's probably better to keep the strings and their counts together in a struct. If anything, this will help you with sorting later. This also offers some simplification: Instead of allocating chunks of 3 bytes, keep a char array of four bytes in the struct, so that all entries can be properly null-terminated. Those don't need to be allocated separately.
Here's an alternative implementation:
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
struct tri {
char str[4]; // trigraph: 3 chars and NUL
int count; // count of occurrences
};
struct stat {
struct tri *tri; // list of trigraphs with counts
int size; // number of trigraphs
};
/*
* Find string 'key' in list of trigraphs. Return the index
* or in the array or -1 if it isn't found.
*/
int find_trigraph(const struct tri *tri, int n, const char *key)
{
for (int i = 0; i < n; i++) {
int j = 0;
while (j < 3 && tri[i].str[j] == key[j]) j++;
if (j == 3) return i;
}
return -1;
}
/*
* Create an array of trigraphs from the input string.
*/
struct stat getSearchArr(char* input, int length)
{
int num = 0;
struct tri *tri = malloc(sizeof(*tri) * (length - 2));
for(int i = 0; i < length - 2; i++) {
int index = find_trigraph(tri, num, input + i);
if (index < 0) {
snprintf(tri[num].str, 4, "%.3s", input + i); // see [1]
tri[num].count = 1;
num++;
} else {
tri[index].count++;
}
}
for(int i = 0; i < num; i++) {
printf("#%d %s: %d\n", i, tri[i].str, tri[i].count);
}
struct stat stat = { tri, num };
return stat;
}
/*
* Driver code
*/
int main(void)
{
char *input = "googleapis.com.wncln.wncln.org";
int length = strlen(input);
struct stat stat = getSearchArr(input, length);
// ... do stuff with stat ...
free(stat.tri);
return 0;
}
Footnote 1: I find that snprintf(str, n, "%.*s", len, str + offset) is useful for copying substrings: The result will not overflow the buffer and it will be null-terminated. There really ought to be a stanard function for this, but strcpy may overflow and strncpy may leave the buffer unterminated.
This answer tries to fix the existing code instead of proposing alternative/better solutions.
After fixing the output
printf("-----string----%s\n", nameArr[i-num]);
in the question, there is still another important problem.
You want to store 3 characters in nameArr[i-num] and allocate space for 3 characters. Later you print is as a string in the code shown above. This requires a trailing '\0' after the 3 characters, so you have to allocate memory for 4 characters and either append a '\0' or initialize the allocated memory with 0. Using calloc instead of malloc would automatically initialize the memory to 0.
Here is a modified version of the source code
I also changed the initialization of the string value and its length in main() to avoid the memory leak.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct strArrIntArr {
int length;
char **charArr;
int *intArr;
};
struct strArrIntArr getSearchArr(char* input, int length) {
struct strArrIntArr nameIndArr;
// flag of same bit
int same;
// flag/index of identical strings
int flag = 0;
// how many identical strings
int num = 0;
// array of split strings
char** nameArr = (char **)malloc(sizeof(char *) * (length - 2));
if ( nameArr == NULL ) exit(0);
// numbers of every split string
int* valueArr = (int* )malloc(sizeof(int) * (length-2));
if ( valueArr == NULL ) exit(0);
// loop length of search string -2 times (3-gram)
for(int i = 0; i<length-2; i++){
if(flag==0){
nameArr[i - num] = (char *)malloc(sizeof(char) * 4);
if ( nameArr[i - num] == NULL ) exit(0);
printf("----i------------%d------\n", i);
printf("----i-num--------%d------\n", i-num);
}
flag = 0;
// compare splitting string with existing split strings,
// if a string exists, it would not be stored
for(int k=0; k<i-num; k++){
same = 0;
for(int j=0; j<3; j++){
if(input[i + j] == nameArr[k][j]){
same ++;
}
}
// identical strings found, if all the three bits are the same
if(same == 3){
flag = 1;
num++;
break;
}
}
// if the current split string doesn't exist yet
// put current split string to array
if(flag == 0){
for(int j=0; j<3; j++){
nameArr[i-num][j] = input[i + j];
valueArr[i-num] = 1;
}
nameArr[i-num][3] = '\0';
}else{
valueArr[flag]++;
}
printf("-----string----%s\n", nameArr[i-num]);
}
// number of N-gram strings
nameIndArr.length = length- 2- num;
// array of N-gram strings
nameIndArr.charArr = nameArr;
nameIndArr.intArr = valueArr;
return nameIndArr;
}
int main(int argc, const char * argv[]) {
int length;
char* input = strdup("googleapis.com.wncln.wncln.org");
length = strlen(input);
// split the search string into N-gram strings
// and count the numbers of every split string
struct strArrIntArr nameIndArr = getSearchArr(input, length);
}
This other answer contains more improvements which I personally would prefer over the modified original solution.

C Flatten 2-D Array of Char* to 1-D

Say I have the following code:
char* array[1000]; // An array containing 1000 char*
// So, array[2] could be 'cat', array[400] could be 'space', etc.
Now, how could I flatten this array into 1-D? Is it possible to do this such that new_1D_array[2] would still be 'cat', new_1D_array[400] would still be 'space', etc.?
You have a one-dimensional array of type pointer-to-char, with 1000 such elements. It's already 1D as far as arrays go, though it could be interpreted as a "jagged 2D array". If you want to convert this into one massive character array, you could do something like so, which requires calculating the size of the buffer you'll need to store it, and then flattening the array.
Note that if you opt to use malloc instead of calloc, you'll have to manually set the last character to '\0' or 0 so that the final result is a NULL-delimited C-style string, and not just a character array, as the latter of the two won't work with C string operations, and the former will.
Code Listing
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(void) {
const char* array[] = { "one", "two", "three", "four" };
size_t length = sizeof(array) / sizeof(char*);
int i;
int sum = 0;
int count = 0;
for (i=0; i<length; i++) {
printf("Element #%d - %s\n", i, array[i]);
sum += strlen(array[i]) + 1;
}
sum++; // Make room for terminating null character
char* buf;
if ((buf = calloc(sum, sizeof(char))) != NULL) {
for (i=0; i<length; i++) {
memcpy(buf+count, array[i], strlen(array[i]));
count += strlen(array[i]) + 1;
buf[count-1] = '#';
}
printf("Output Buffer: %s\n", buf);
printf("Buffer size:%d - String Length:%d\n", sum, strlen(buf));
free(buf);
buf = NULL;
}
return 0;
}
Sample Output
Element #0 - one
Element #1 - two
Element #2 - three
Element #3 - four
Output Buffer: one#two#three#four#
Buffer size:20 - String Length:19
The above answer beat me to the puch and looks great, but I'll finish my thoughts here.
In this version every 11th byte of flatArray will contain the start of the strings from the original array, making it very easy to find the original strings from the ones before - i.e. string index 2 would start at 2*11 == index 22 and string 400 would start at 400 * 11 == index 4400. In this way, you would not need to iterate through the flat array counting terminators to find your old strings. The cost of this being that the flat array takes a bit more memory than the original.
char* array[1000];
// Malloc new buffer
char *flatArray = malloc(length * 1100);
for(i=0; i<1000; i++)
{
strncpy(&flatArray[i * 11], array[i], 10);
flatArray[i * 11 + 10] = '\0';
}

Array copying C programming

I have the code as:
mid = 3;
for(i=0;i<9;i++)
{
if(i == 9-mid)
num[i] = mid;
else
num[i] = 0;
printf("%d", num[i]);
}
which gives the result of "000000300".
What I try to do is to store "000000300" as an element of another array, i.e.
unsigned int array[0] = 000000300;
Any ideas of how to do this in C? Thanks~
If you want to copy the calculated string "000000300" you will need to allocate some memory and store it in a char * array:
// num is a char array containing "000000300".
char *stored = (char *)malloc(strlen(num) + 1);
if (stored == NULL) {
// This means that there is no memory available.
// Unlikely to happen on modern machines.
}
strcpy(stored, num);

Remove char from char* and return char*

I have one char array and I want to delete chars that satisfy my condition. Example I have a char array A={1,-1,0 ,1 ,-1} and I want to delete elements that equal -1. That mean output is {1,0,1}, and I want to check how many element in the array. In my example is 3. Can you help me please?
char* delete_char(char* sourceArray, char inputChar)
{
char* out=NULL;
//Need to malloc memory. But I don't know how many size will allocate because it depends on how many element that don't equal -1
return out;
}
int sizeofArray(char* sourceArray)
{
return size;
}
You have some strategies:
Calculate the exact size before allocating.
Estimate a size.
Allocate a big size memory (you probably know maximum size in worse case).
In two later cases, you can use realloc to shrink the memory. In your code, the estimated size is strlen(sourceArray)+1 if the array is a zero-terminated string, because by deleting the result is less and equal to it.
First of all, when you are using char* as an array, you also need to provide information about the length of that array (how many items it contains). Usualy this is done by a second parameter.
In your case: delete_char(char *inputArray, char inputArraySize, char inputChar).
Then you should allocate your result array to be the size of your input array (because it can contain at most as much items as the input array).
After that, you should iterate through every item in the input array and if the item fulfills your condition, add it into the result array. Of course, you have to provide also the size of the output array (for instance in an another output parameter), so you'll be able to work with it.
And lastly, when your done with working with the resulting array, don't forget do deallocate all of its memory (that means deallocate it as it was the size of the original input array, because it actially is).
You can write own function like that.
int size(char *ptr)
{
int offset = 0;
int count = 0;
while (*(ptr + offset) != '\0')
{
++count;
++offset;
}
return count;
}
Here it is:
#include <string.h>
char* delete_char(char* sourceArray, char inputChar)
{
int iNr = 0,iSize,j = 0;
iSize = strlen( sourceArray );
for( int i = 0; i < iSize; i++ )
if( sourceArray[i] == inputChar )
iNr ++;
char *newarray = new char[iNr +1];
for( int i = 0; i < iSize; i++ )
{
if( sourceArray[i] != inputChar )
newarray[j++] = sourceArray[i];
}
return newarray;
}
int sizeofArray(char* sourceArray)
{
return strlen( sourceArray );
}
PS TESTED. It works but may not be very efficient cause you check it 2 times.
You can scan the array to determine the number of elements you are removing, then allocate and appropriate memory, then copy. For example:
int sizeNeeded = 0;
for (int i = 0; i < sizeofArray(sourceArray; i++) {
if (sourceArray[I] != inputChar) sizeNeeded++;
}
char *rv = (char *) malloc(sizeNeeded * sizeOf(char));
int j = 0;
for (int i = 0; i < sizeofArray(sourceArray; i++) {
if (sourceArray[I] != inputChar) rv[j++] = sourceArray[i];
}
I did not try to compile this code but it should convey the idea

Resources