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).
