As you can see in the code I am trying to print the items for the array by calling the viewArray function but it is not printing after the call. I tried to double the capacity of the array by using the doubleArray function and I also tried to halve the size of the Array using halfArray function.
#include<stdio.h>
#include<stdlib.h>
struct DynamicArray
{
int capacity;
int lastIndex;
int *ptr;
};
struct DynamicArray *createArray(int cap)
{
struct DynamicArray *arr;
arr=(struct DynamicArray*)malloc(sizeof(struct DynamicArray));
arr->ptr=(int*)malloc(sizeof(int)*cap);
arr->capacity=cap;
arr->lastIndex=-1;
return arr;
};
// Function to double the capacity of array
void doubleArray(struct DynamicArray *arr)
{
int *temp;
temp=(int*)malloc(sizeof(int)*arr->capacity*2);
for(int i=0; i<=arr->lastIndex; i )
temp[i]=arr->ptr[i];
free(arr->ptr);
arr->ptr=temp;
arr->capacity*=2;
}
// Function to half the size of an Array
void halfArray(struct DynamicArray *arr)
{
int *temp;
temp=(int*)malloc(sizeof(int)*arr->capacity/2);
for(int i=0; i<=arr->lastIndex; i )
temp[i]=arr->ptr[i];
free(arr->ptr);
arr->ptr=temp;
arr->capacity/=2;
}
//Function to append an element in Array
void append(struct DynamicArray *arr,int data)
{
if(arr->lastIndex 1>arr->capacity)
{
doubleArray(arr);
}
arr->ptr[arr->lastIndex 1]=data;
arr->lastIndex =1;
}
// Function to insert an element in array
void insert(struct DynamicArray *arr,int pos,int data)
{
if(pos<0 || pos>arr->lastIndex 1)
{
printf("\nInvalid Index!!\n");
}
else
{
if(arr->lastIndex 1>arr->capacity)
{
doubleArray(arr);
}
for(int i=arr->lastIndex; i>=pos; i--)
{
arr->ptr[i 1]=arr->ptr[i];
}
arr->ptr[pos]=data;
arr->lastIndex =1;
}
// Function to delete an element from an array
void delete(struct DynamicArray *arr,int pos)
{
if(pos<0 || pos>arr->lastIndex 1)
{
printf("\nInvalid Index\n");
}
else
{
if(count(arr)<=arr->capacity/2)
{
halfArray(arr);
}
for(int i=pos; i<arr->lastIndex; i )
{
arr->ptr[i]=arr->ptr[i 1];
}
arr->lastIndex-=1;
}
// Function to print the Array elements
void viewArray(struct DynamicArray *arr)
{
for(int i=0; i<=arr->lastIndex; i )
{
printf("\n%d\t",arr->ptr[i]);
}
}
int main()
{
int choice;
struct DynamicArray *arr;
while(1)
{
printf("1:- Create an Array\n");
printf("2:- Append an Element in an Array\n");
printf("3:- Insert an Element in an Array\n");
printf("4:- Delete an Element in an Array\n");
printf("5:- View Array\n");
printf("\nEnter your Choice:-\t");
scanf("%d",&choice);
switch(choice)
{
case 1:
arr=createArray(10);
printf("\nArray Created successfully!!\n\n");
break;
case 2:
append(arr,99);
append(arr,45);
append(arr,67);
append(arr,21);
append(arr,32);
printf("\nElement append successfully!!\n\n");
break;
case 3:
insert(arr,2,89);
break;
case 4:
delete(arr,2);
printf("\nElement deleted successfully!!\n\n");
break;
case 5:
viewArray(arr);
break;
}
}
return 0;
}
CodePudding user response：
Let's start with problems in the structure. You should not use int to index the array. You should use unsigned type for that. What's more I think that the lastIndex is a bad idea - use the size of the array, it is always equal to lastIndex 1, so you will avoid a lot of adding later in the code.
The first function: createArray. You do not check whether malloc returned NULL. What's more your way of calling it is not the best. It's not wrong, but I highly recommend reading this post.
Now, the second function: 'doubleArray'. Have you heard of 'realloc'? You should use it here. The same problem in the the 'halfArray' function.
About append: I am pretty sure that the condition in the if clause is incorrect. It should be >= not >. It would be more obvious if you used size instead of lastIndex.
Insert: You should print errors to stderr with fprintf(stderr, error_message); What's more, the same error in if clause.
Delete: The same as insert and I think you should halve the array AFTER you move everything.
After considering everything, the code below should work:
#include<stdio.h>
#include<stdlib.h>
struct DynamicArray
{
size_t capacity;
size_t size;
int *ptr;
};
struct DynamicArray *createArray(size_t cap)
{
struct DynamicArray *arr = malloc(sizeof *arr);
if (arr) {
arr->ptr = calloc(cap, sizeof(*arr->ptr));
if (arr->ptr) {
arr->capacity = cap;
arr->size = 0;
} else {
free(arr);
}
}
return arr;
};
// Function to double the capacity of array
void doubleArray(struct DynamicArray *arr)
{
int *temp = realloc(arr->ptr, sizeof(*arr->ptr) * (arr->capacity * 2));
if (temp) {
arr->ptr = temp;
arr->capacity *= 2;
} else {
// You should make it possible to return failure.
}
}
// Function to half the size of an Array
void halfArray(struct DynamicArray *arr)
{
int *temp = realloc(arr->ptr, sizeof(*arr->ptr) * (arr->capacity / 2));
if (temp) {
arr->ptr = temp;
arr->capacity /= 2;
} else {
// You should make it possible to return failure.
}
}
//Function to append an element in Array
void append(struct DynamicArray *arr,int data)
{
if(arr->size >= arr->capacity)
{
doubleArray(arr);
}
arr->ptr[arr->size] = data;
arr->size;
}
// Function to insert an element in array
void insert(struct DynamicArray *arr, size_t pos, int data)
{
if (pos > arr->size)
{
// Errors should be reported to stderr
fprintf(stderr, "\nInvalid Index!!\n");
}
else
{
if (arr->size >= arr->capacity)
{
doubleArray(arr);
}
for (size_t i = arr->size; i > pos; --i)
{
arr->ptr[i] = arr->ptr[i - 1];
}
arr->ptr[pos]=data;
arr->size;
}
}
// Function to delete an element from an array
void delete(struct DynamicArray *arr, size_t pos)
{
if(pos > arr->size)
{
fprintf(stderr, "\nInvalid Index\n");
}
else
{
// I do not know what "count" is.
// And I think you should halve an array after moving data.
/*if(count(arr)<=arr->capacity/2)
{
halfArray(arr);
}*/
arr->size -= 1;
for (size_t i = pos; i < arr->size; i)
{
arr->ptr[i] = arr->ptr[i 1];
}
}
}
// Function to print the Array elements
void viewArray(struct DynamicArray *arr)
{
for(size_t i = 0; i < arr->size; i )
{
printf("\n%d\t",arr->ptr[i]);
}
}
int main()
{
int choice;
struct DynamicArray *arr;
while(1)
{
printf("1:- Create an Array\n");
printf("2:- Append an Element in an Array\n");
printf("3:- Insert an Element in an Array\n");
printf("4:- Delete an Element in an Array\n");
printf("5:- View Array\n");
printf("\nEnter your Choice:-\t");
scanf("%d",&choice);
switch(choice)
{
case 1:
arr=createArray(10);
printf("\nArray Created successfully!!\n\n");
break;
case 2:
append(arr,99);
append(arr,45);
append(arr,67);
append(arr,21);
append(arr,32);
printf("\nElement append successfully!!\n\n");
break;
case 3:
insert(arr,2,89);
break;
case 4:
delete(arr,2);
printf("\nElement deleted successfully!!\n\n");
break;
case 5:
viewArray(arr);
break;
}
}
return 0;
}