1.3 Array Operations | Deletion from Array | Explanation with Code |
Data Structure
Jenny's Lectures CS IT
In this lesson, we will discuss the deletion operation in arrays.
We will use an example array of size 5 to explain the process of
deleting data from a specific position, beginning, and end of
the array. We will also write the code and analyze the time
complexity of the operation.
First, we initialize an array of size 50 but ask the user for the
number of elements they want to insert. We then populate the
array with the user's input and ask them which position they
want to delete data from. For example, if they choose position
2 (index 1), we cannot leave that space blank. Instead, we shift
the elements to fill the empty space and decrease the size of
the array by 1.
We start a loop to shift the elements to the left, starting from
the index before the position chosen by the user until the
second last index of the array. We shift the element at index
i+1 to index i and continue until the end of the loop,
overwriting the deleted element. If we want to print the
deleted data, we store it in a separate variable before shifting
the elements.
We provide the code for the deletion operation, where we ask
the user for the position to delete, check if it's a valid position,
and then start the loop to shift the elements.
int size = 5; int arr[size]; int pos, i; int
item; // ask user for position to delete
printf("Enter position to delete: "); scanf("%d",
&pos); // check if valid position if (pos <= 0
|| pos > size) { printf("Invalid position"); }
else if (pos == size) { printf("No data at
position %d", pos); } else { // start loop to
shift elements for (i = pos-1; i < size-1; i++) {
arr[i] = arr[i+1]; } size--; // decrease size
of array }
Data Structure
Jenny's Lectures CS IT
In this lesson, we will discuss the deletion operation in arrays.
We will use an example array of size 5 to explain the process of
deleting data from a specific position, beginning, and end of
the array. We will also write the code and analyze the time
complexity of the operation.
First, we initialize an array of size 50 but ask the user for the
number of elements they want to insert. We then populate the
array with the user's input and ask them which position they
want to delete data from. For example, if they choose position
2 (index 1), we cannot leave that space blank. Instead, we shift
the elements to fill the empty space and decrease the size of
the array by 1.
We start a loop to shift the elements to the left, starting from
the index before the position chosen by the user until the
second last index of the array. We shift the element at index
i+1 to index i and continue until the end of the loop,
overwriting the deleted element. If we want to print the
deleted data, we store it in a separate variable before shifting
the elements.
We provide the code for the deletion operation, where we ask
the user for the position to delete, check if it's a valid position,
and then start the loop to shift the elements.
int size = 5; int arr[size]; int pos, i; int
item; // ask user for position to delete
printf("Enter position to delete: "); scanf("%d",
&pos); // check if valid position if (pos <= 0
|| pos > size) { printf("Invalid position"); }
else if (pos == size) { printf("No data at
position %d", pos); } else { // start loop to
shift elements for (i = pos-1; i < size-1; i++) {
arr[i] = arr[i+1]; } size--; // decrease size
of array }
