falls after input
-
21-12-2019 - |
Pergunta
What have I done wrong here? It falls after I input count
and then my array
It must be something with memory allocation, but i tried many things and none of them helped. thanks for responding
struct _arr {
size_t count;
int* arr;
};
typedef struct _arr array_t;
array_t array_create(int* arr, size_t count){
array_t* newArr;
newArr = (array_t*)malloc(sizeof(count)+sizeof(int)*count);
newArr->count = count;
newArr->arr = arr;
return *newArr;
}
array_t array_get(FILE* file){
int* arr = NULL;
size_t count;
array_t arr_t;
int i = 0;
if (!file) return;
if (!fscanf(file, "%u", &count)) return;
arr_t = array_create(arr, count);
for (i = 0; i < arr_t.count; i++){
if (!fscanf(file, "%d", &arr_t.arr[i])) return;
}
for (i = 0; i<arr_t.count; i++)
printf("%d ", arr_t.arr[i]);
printf("\n");
return arr_t;
}
int main(){
array_t arr;
int i = 0;
arr = array_get(stdin);
for (i = 0; i<arr.count; i++)
printf("%d ", arr.arr[i]);
getch();
return 0;
}
Solução
WhozCraig's crystal ball says your problem is in array_create()
. Specifically, the field arr
is not allocated properly. Your array_create()
should look something like this:
array_t array_create(int length)
{
array_t res = {length, NULL};
if (length > 0) {
res.arr = malloc(length * sizeof(*res.arr));
if(res.arr == NULL) {
printf("malloc(%d) failed\n", length * sizeof(*res.arr));
exit(1);
}
}
return res;
}
You also need to fix those empty returns. Maybe you just want to print a message and exit.
Update Mon Nov 18 16:13:48 CST 2013
This is a whole different version that allocates an array_t from the heap. The error handling is kind of ugly ( all those places that return 0; ). This should work, the other worked too, but maybe an array_t on the heap is what you are looking for.
#include <stdio.h>
#include <stdlib.h>
typedef struct {
size_t count;
int *arr;
} array_t;
array_t *array_create(size_t count){
array_t *newArr = malloc(sizeof(array_t));
if(newArr == 0) return 0;
newArr->count = count;
newArr->arr = calloc(sizeof(int),count);
if(newArr->arr == 0) return 0;
return newArr;
}
array_t *array_get(FILE* file){
size_t count;
array_t *arr;
int i = 0;
if (!file) return 0;
if (!fscanf(file, "%zu", &count)) return 0;
arr = array_create(count);
if(arr == 0) return 0;
for (i = 0; i < arr->count; i++){
if (!fscanf(file, "%d", &arr->arr[i])) return 0;
}
for (i = 0; i<arr->count; i++)
printf("%d ", arr->arr[i]);
printf("\n");
return arr;
}
int main(void) {
array_t *arr;
int i = 0;
arr = array_get(stdin);
if(arr == 0) return -1;
for (i = 0; i<arr->count; i++)
printf("%d ", arr->arr[i]);
getch(); // getch is windows
return 0;
}
Outras dicas
according to me you are trying to returning the value that present on that address having pointer. so just simply return newArr