Data Structures and Algorithms
Sequential Data Structures: Linked Lists & Arrays
executive summary
Store:
a sequence of elements
Manipulate:
add/remove elements (at one of the ends or in the middle)
update an exisiting element (at one of the ends or in the middle)
link to companion notes · visualgo (arrays) · visualgo (linked lists)
Approaches: linked lists, arrays, dynamic arrays
Sets & Sequential Data
The atomic types have served us well,
but it is now time to build on them.
Say you are a real estate agent &
need to reserve some houses in a new
apartment complex.
The builder can block any contiguous chunk
of N houses for you.
Your list of clients may evolve over time.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
⛔️
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
⛔️
👇
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
🔑
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
🔑
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
🔑
🔑
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
🔑
🔑
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
🔑
🔑
🔑
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
🔑
🔑
🔑
Say you are a real estate agent &
need to reserve some houses in a new apartment complex.
🔑
🔑
🔑
🔑
Arrays
Linked Lists
Looking up the i-th element
Adding a new element at the start
Adding a new element at the end
Removing the i-th element
instant
instant
instant*
\(\approx\) n
\(\approx\) n
\(\approx\) n-i
\(\approx\) i
Adding a new element at the i-th location
\(\approx\) n-i
\(\approx\) min( i,n-i)**
\(\approx\) min( i,n-i)**
* Assuming we have a tail pointer.
** Assuming we have backward pointers.
Why can't everything be fast?
DYNAMIC ARRAYS
Whenever the array overflows, double its size.
Total cost = total #insertions + total #copy operations
Total cost = total #insertions + total #copy operations
\(\leqslant\) N + N = 2N
...since each copy can be associated with a distinct insert,
& the #inserts = N; so #copy operations \(\leqslant\) N
Why can't everything be fast?
DYNAMIC ARRAYS
Whenever the array overflows, double its size.
TBA
Notes and slides on implementation details
Examples and problems
DSA · Sequential Data Structures
By Neeldhara Misra
DSA · Sequential Data Structures
Data Structures: Just some Structured Data
