1.3 Array Operations | Deletion from Array |
Explanation with Code | Data Structure
Jenny's Lectures CS IT
I will discuss the deletion operation using the example I used in a
previous video. Understanding how to delete data from a specific
position will also make it easier to delete data from the beginning
or end of the array. I declared an array of size 50 in the previous
code, and the memory manager allocated 200 bytes of memory
for this array. One variable, size, is used to determine the
maximum size of the array. If the user wants to insert only 10 or 5
elements, for example, I will ask them how much size they want
for the array, and this will allocate an additional 4 bytes of
memory. The user will then enter the elements of the array, which
will be initialized at runtime. To delete data from the array, I will
ask the user from which position they want to delete the data. For
example, if they want to delete data from position 2, I will shift
the values from position 3 to 4 and reduce the size of the array by
1. I will start a loop from the position to be deleted to the end of
the array and shift the values to the left. To print the updated
array after deletion, I will use a for loop to print each element of
the array. It's important to check the validity of the position
entered by the user before deleting data from the array. If the
position is invalid, such as -1 or greater than the size of the array,
I will print "invalid position". If there is no data in the array, it's
also an underflow condition and the data cannot be deleted.
When deleting data from the end of the array, I will simply
decrement the size of the array. When deleting data from the
beginning of the array, I will shift all the elements to the left and
decrement the size of the array. The time complexity of the
deletion operation depends on the position from which the data is
to be deleted. If the data is to be deleted from a specific position,
all the elements to the right of that position must be shifted to the
left, which takes O(n) time. However, if the array is unsorted, a
quicker algorithm is to pick the last element of the array and put
it in the position to be deleted. The best algorithm for this case
takes constant time, which is O(1).
Explanation with Code | Data Structure
Jenny's Lectures CS IT
I will discuss the deletion operation using the example I used in a
previous video. Understanding how to delete data from a specific
position will also make it easier to delete data from the beginning
or end of the array. I declared an array of size 50 in the previous
code, and the memory manager allocated 200 bytes of memory
for this array. One variable, size, is used to determine the
maximum size of the array. If the user wants to insert only 10 or 5
elements, for example, I will ask them how much size they want
for the array, and this will allocate an additional 4 bytes of
memory. The user will then enter the elements of the array, which
will be initialized at runtime. To delete data from the array, I will
ask the user from which position they want to delete the data. For
example, if they want to delete data from position 2, I will shift
the values from position 3 to 4 and reduce the size of the array by
1. I will start a loop from the position to be deleted to the end of
the array and shift the values to the left. To print the updated
array after deletion, I will use a for loop to print each element of
the array. It's important to check the validity of the position
entered by the user before deleting data from the array. If the
position is invalid, such as -1 or greater than the size of the array,
I will print "invalid position". If there is no data in the array, it's
also an underflow condition and the data cannot be deleted.
When deleting data from the end of the array, I will simply
decrement the size of the array. When deleting data from the
beginning of the array, I will shift all the elements to the left and
decrement the size of the array. The time complexity of the
deletion operation depends on the position from which the data is
to be deleted. If the data is to be deleted from a specific position,
all the elements to the right of that position must be shifted to the
left, which takes O(n) time. However, if the array is unsorted, a
quicker algorithm is to pick the last element of the array and put
it in the position to be deleted. The best algorithm for this case
takes constant time, which is O(1).
