Data Structures and Algorithms: Using Python

this lecture demonstrates solving gas station problem on a circular route using python, showing that total gas must meet or exceed total cost and applying a pass to locate start.

Find the first occurrence of a needle in a haystack by iterating indices and comparing slices, returning the index or -1 if not found or if the needle is empty.

Use the two-pointer sliding window to compute the minimum-length subarray with sum at least the target in a positive-integer array, returning zero if impossible.

Learn the game of life on an m by n grid, applying eight-neighbor rules to update cells in place using a dictionary to track neighbor counts.

Group the strings into anagrams by sorting each string to form a key, then gather groups in a dictionary and return the results.

Explore solving the two sum problem with a dictionary to achieve O(n) time, returning indices of the two numbers that add up to the target in Python.

learn how to determine if a number is happy by repeatedly summing the squares of its digits, using a dictionary to detect cycles and return true or false.

Merge intervals teaches how to sort intervals by start values and merge overlapping ones into non-overlapping ranges using Python, illustrating with examples and analyzing an O(n) solution.

Implement a Python solution to validate a string of brackets using a stack and a dictionary mapping closing to opening brackets.

Learn to build a basic calculator in Python that evaluates expressions with digits, plus and minus signs, and parentheses using a stack, number, result, and sign handling, achieving O(n) time.

Add two numbers represented by reversed linked lists and manage carries to produce the sum as a linked list, with a Python solution using a dummy head.

Merge two sorted linked lists by comparing node values and splicing nodes with a dummy head and current pointer in a Python solution, and handle nodes after one list ends.

Explore the design of an lru cache using a hash map and a stack to support get and put operations, evicting the least recently used item when capacity is exceeded.

Solve maximum depth of a binary tree using recursion, applying one plus the max of left and right subtrees, with an optional iterative stack approach in Python.

Solve the path sum problem by pre-order dfs from root to leaf, accumulating node values to match a target sum. The lecture presents a Python solution.