Python Problem-Solving Journal

My LeetCode solutions in Python, with problem statements and a topic index maintained by LeetHub v2.

Browse the solutions

Problem	Python solution
0001 two sum	Source
0026 remove duplicates from sorted array	Source
0029 divide two integers	Source
0030 substring with concatenation of all words	Source
0042 trapping rain water	Source
0069 sqrtx	Source
0189 rotate array	Source
0283 move zeroes	Source
0744 find smallest letter greater than target	Source
1071 greatest common divisor of strings	Source
1846 maximum element after decreasing and rearranging	Source
3010 divide an array into subarrays with minimum cost i	Source
3020 find the maximum number of elements in subset	Source

How I use this repository

• Practice translating a problem into a clear algorithm.
• Compare approaches and reason about edge cases.
• Build familiarity with arrays, strings, two pointers, binary search, and other patterns.

Solutions use LeetCode's execution format. Open the linked problem statement and use its test harness to run a solution; most files are not standalone command-line programs.

Automatically maintained topic index

The section below is generated by LeetHub and may change when new solutions are synced.

LeetCode Topics

Array

0001-two-sum
0026-remove-duplicates-from-sorted-array
0042-trapping-rain-water
0078-subsets
0189-rotate-array
0283-move-zeroes
0744-find-smallest-letter-greater-than-target
1846-maximum-element-after-decreasing-and-rearranging
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3020-find-the-maximum-number-of-elements-in-subset

Greedy

1846-maximum-element-after-decreasing-and-rearranging

Sorting

1846-maximum-element-after-decreasing-and-rearranging
3010-divide-an-array-into-subarrays-with-minimum-cost-i

Hash Table

0001-two-sum
0030-substring-with-concatenation-of-all-words
3020-find-the-maximum-number-of-elements-in-subset

Enumeration

3010-divide-an-array-into-subarrays-with-minimum-cost-i
3020-find-the-maximum-number-of-elements-in-subset

Binary Search

0069-sqrtx
0744-find-smallest-letter-greater-than-target

Two Pointers

0026-remove-duplicates-from-sorted-array
0042-trapping-rain-water
0189-rotate-array
0283-move-zeroes

Math

0029-divide-two-integers
0069-sqrtx
0189-rotate-array
1071-greatest-common-divisor-of-strings

Dynamic Programming

0042-trapping-rain-water

Stack

0042-trapping-rain-water

Monotonic Stack

0042-trapping-rain-water

String

0030-substring-with-concatenation-of-all-words
1071-greatest-common-divisor-of-strings

Bit Manipulation

0029-divide-two-integers
0078-subsets

Sliding Window

0030-substring-with-concatenation-of-all-words

Backtracking

0078-subsets