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Python Coding Challenges

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925 challenges 556 easy 323 medium 46 hard
Graphs & Graph Algorithms hard

Minimum Cut

Given an undirected graph in adjacency-list form, return the size of the minimum edge cut that disconnects the graph.

graphs max-flow min-cut
+40 pts 35m
Graphs & Graph Algorithms medium

Bipartite Graph Check

Implement a function to check if an undirected graph is bipartite using graph coloring.

graphs bfs coloring
+25 pts 30m
Graphs & Graph Algorithms medium

Graph Coloring

Given an undirected graph, determine if it can be colored with two colors such that adjacent vertices have different colors.

graph bipartite bfs
+20 pts 20m
Graphs & Graph Algorithms medium

Course Schedule Can Finish

Given numCourses and prerequisites, return whether all courses can be finished without cyclic dependencies.

graph cycle topological
+25 pts 30m
Graphs & Graph Algorithms medium

Graph Valid Tree

Determine if n nodes and an edge list form a valid tree (connected and acyclic).

graph dfs bfs
+25 pts 30m
Graphs & Graph Algorithms medium

Cheapest Flights Within K Stops

Implement a function to compute the cheapest flight price from source to destination with at most K stops in a directed weighted graph.

graphs shortest-path dp
+30 pts 30m
Graphs & Graph Algorithms easy

Keys and Rooms

A classic graph traversal challenge: check if all rooms are reachable from room 0 using keys found in visited rooms.

graph dfs bfs
+10 pts 20m
Graphs & Graph Algorithms hard

Swim in Rising Water

Find the minimum time needed to swim from the top-left to the bottom-right of a grid where water level rises and you can only move to cells with elevation ≤ current time.

graph minimax priority-queue
+30 pts 20m
Graphs & Graph Algorithms medium

Surrounded Regions

Given an M×N grid of 'X' and 'O', capture all regions of 'O' that are completely surrounded by 'X'.

graph bfs grid
+25 pts 30m
Graphs & Graph Algorithms medium

Course Schedule Ordering

Determine a valid sequence to complete all courses respecting prerequisite constraints.

graph topological-sort bfs
+30 pts 30m
Graphs & Graph Algorithms medium

Minimum Height Trees

Given an undirected tree, find all root nodes that minimize the height of the tree.

graphs bfs topological
+30 pts 30m
Graphs & Graph Algorithms medium

Open the Lock BFS

Implement a BFS solution to find the minimum number of turns needed to open a 4-wheel lock, avoiding a set of deadends.

bfs strings graph
+25 pts 30m
Graphs & Graph Algorithms medium

Minimum Genetic Mutation

Implement a function to compute the minimum number of single-character mutations needed to transform one gene string into another, using a given bank of valid mutations.

bfs graph string
+30 pts 30m
Graphs & Graph Algorithms medium

Possible bipartition

Given N people and a list of mutual dislikes, check if they can be divided into two groups with no dislike inside a group.

bipartite graph bfs
+25 pts 25m
Graphs & Graph Algorithms medium

Jump Game on Graph

Implement a function that determines if you can reach the last node of a directed graph by jumping from node 0 to node n-1 using edges.

graphs bfs reachability
+25 pts 30m

Showing 1–15 of 15 challenges · Graphs & Graph Algorithms

Graphs & Graph Algorithms — Python coding challenges

What you will find here

This page lists graphs & graph algorithms challenges — real Python problems you solve in the browser IDE with instant test feedback. Each challenge includes a clear brief, starter code, and automated checks.

Challenges vs tutorials and quizzes

Challenges test what you can build under constraints. For guided teaching, use our Python tutorials. For quick checks, try quizzes or copy snippets from code samples.