> For the complete documentation index, see [llms.txt](https://algorithm.prettylog.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard.md).

# Hard

- [Prim’s Algorithm](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/prims-algorithm.md)
- [Dijkstra’s Algorithm](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/dijkstras-algorithm.md)
- [Kruskal’s algorithm vs Prim’s algorithm](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/kruskals-algorithm-vs-prims-algorithm.md)
- [Topological Sort](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/topological-sort.md)
- [Max Sum Increasing Subsequence](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/max-sum-increasing-subsequence.md)
- [Find Nodes Distance K](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/find-nodes-distance-k.md)
- [Max Path Sum In Binary Tree](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/max-path-sum-in-binary-tree.md)
- [Validate Three Nodes](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/validate-three-nodes.md)
- [Same BST ?](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/same-bst.md)
- [Zigzag Traverse](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/zigzag-traverse.md)
- [Min Rewards](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/min-rewards.md)
- [Largest Range](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/largest-range.md)
- [Subarray Sort](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/subarray-sort.md)
- [Four Number Sum](https://algorithm.prettylog.com/algorithm-problems/algoexpert/hard/four-number-sum.md)