I am solving this problem On HackerRank , in this i just have to complete function for COUNTING SORT , after i have done sorting and stored it in (arf),i try to debug the error by printing arf elements using for loop and its giving me correct output , but when i am returning (arf) in main function its printing blank;
i am attaching question and output screenshot for ref, Question & Fxn Desc
Input & Myoutput
Expected Output & MyDEBUG OUTPUT
i am facing this dynamic array returning issue in almost 3 questions. (same issue like when i try to print elements using for loop, they came correct but as i return that pointer, it prints Blank output ).
//CODE STARTS
#include <assert.h>
#include <ctype.h>
#include <limits.h>
#include <math.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char* readline();
char* ltrim(char*);
char* rtrim(char*);
char** split_string(char*);
int parse_int(char*);
/*
* Complete the 'countingSort' function below.
*
* The function is expected to return an INTEGER_ARRAY.
* The function accepts INTEGER_ARRAY arr as parameter.
*/
/*
* To return the integer array from the function, you should:
* - Store the size of the array to be returned in the result_count variable
* - Allocate the array statically or dynamically
*
* For example,
* int* return_integer_array_using_static_allocation(int* result_count) {
* *result_count = 5;
*
* static int a[5] = {1, 2, 3, 4, 5};
*
* return a;
* }
*
* int* return_integer_array_using_dynamic_allocation(int* result_count) {
* *result_count = 5;
*
* int *a = malloc(5 * sizeof(int));
*
* for (int i = 0; i < 5; i++) {
* *(a + i) = i + 1;
* }
*
* return a;
* }
*
*/
// SUSPECT THIS FUNCTION
int* countingSort(int arr_count, int* arr, int* result_count) {
int * arf;
int temp;
int count = 0;
arf = (int *)calloc(100,sizeof(int));
for(int j = 0;j<arr_count;j++)
{
arf[j] = 0;
}
for(int i = 0;i<arr_count;i++)
{
temp = *(arr+i);
arf[temp] +=1;
}
for(int j = 0;j<arr_count;j++) // I PRINTED OUTPUT FROM HERE AND ITS CORRECT
{
printf("%d ",arf[j]); //MYDEBUG OUTPUT
}
return arf; //BUT WHEN I AM RETURNING PTR(arf) in main fxn it is printing nothing
}
int main()
{
FILE* fptr = fopen(getenv("OUTPUT_PATH"), "w");
int n = parse_int(ltrim(rtrim(readline())));
char** arr_temp = split_string(rtrim(readline()));
int* arr = malloc(n * sizeof(int));
for (int i = 0; i < n; i++) {
int arr_item = parse_int(*(arr_temp + i));
*(arr + i) = arr_item;
}
int result_count;
int* result = countingSort(n, arr, &result_count);
for (int i = 0; i < result_count; i++) {
fprintf(fptr, "%d", *(result + i));
if (i != result_count - 1) {
fprintf(fptr, " ");
}
}
fprintf(fptr, "\n");
fclose(fptr);
return 0;
}
char* readline() {
size_t alloc_length = 1024;
size_t data_length = 0;
char* data = malloc(alloc_length);
while (true) {
char* cursor = data + data_length;
char* line = fgets(cursor, alloc_length - data_length, stdin);
if (!line) {
break;
}
data_length += strlen(cursor);
if (data_length < alloc_length - 1 || data[data_length - 1] == '\n') {
break;
}
alloc_length <<= 1;
data = realloc(data, alloc_length);
if (!data) {
data = '\0';
break;
}
}
if (data[data_length - 1] == '\n') {
data[data_length - 1] = '\0';
data = realloc(data, data_length);
if (!data) {
data = '\0';
}
} else {
data = realloc(data, data_length + 1);
if (!data) {
data = '\0';
} else {
data[data_length] = '\0';
}
}
return data;
}
char* ltrim(char* str) {
if (!str) {
return '\0';
}
if (!*str) {
return str;
}
while (*str != '\0' && isspace(*str)) {
str++;
}
return str;
}
char* rtrim(char* str) {
if (!str) {
return '\0';
}
if (!*str) {
return str;
}
char* end = str + strlen(str) - 1;
while (end >= str && isspace(*end)) {
end--;
}
*(end + 1) = '\0';
return str;
}
char** split_string(char* str) {
char** splits = NULL;
char* token = strtok(str, " ");
int spaces = 0;
while (token) {
splits = realloc(splits, sizeof(char*) * ++spaces);
if (!splits) {
return splits;
}
splits[spaces - 1] = token;
token = strtok(NULL, " ");
}
return splits;
}
int parse_int(char* str) {
char* endptr;
int value = strtol(str, &endptr, 10);
if (endptr == str || *endptr != '\0') {
exit(EXIT_FAILURE);
}
return value;
}
//CODE END
INPUT- 100
63 25 73 1 98 73 56 84 86 57 16 83 8 25 81 56 9 53 98 67 99 12 83 89 80 91 39 86 76 85 74 39 25 90 59 10 94 32 44 3 89 30 27 79 46 96 27 32 18 21 92 69 81 40 40 34 68 78 24 87 42 69 23 41 78 22 6 90 99 89 50 30 20 1 43 3 70 95 33 46 44 9 69 48 33 60 65 16 82 67 61 32 21 79 75 75 13 87 70 33
Myoutput -
Expected Output - 0 2 0 2 0 0 1 0 1 2 1 0 1 1 0 0 2 0 1 0 1 2 1 1 1 3 0 2 0 0 2 0 3 3 1 0 0 0 0 2 2 1 1 1 2 0 2 0 1 0 1 0 0 1 0 0 2 1 0 1 1 1 0 1 0 1 0 2 1 3 2 0 0 2 1 2 1 0 2 2 1 2 1 2 1 1 2 2 0 3 2 1 1 0 1 1 1 0 2 2
MydebugOutput - 0 2 0 2 0 0 1 0 1 2 1 0 1 1 0 0 2 0 1 0 1 2 1 1 1 3 0 2 0 0 2 0 3 3 1 0 0 0 0 2 2 1 1 1 2 0 2 0 1 0 1 0 0 1 0 0 2 1 0 1 1 1 0 1 0 1 0 2 1 3 2 0 0 2 1 2 1 0 2 2 1 2 1 2 1 1 2 2 0 3 2 1 1 0 1 1 1 0 2 2