Concepts80
0-1 BFS
0-1 BFS is a shortest path algorithm specialized for graphs whose edge weights are only 0 or 1.
Depth-First Search (DFS)
Depth-First Search (DFS) explores a graph by going as deep as possible along each path before backtracking.
2D Prefix Sum
A 2D prefix sum (also called an integral image) lets you compute the sum of any axis-aligned sub-rectangle in constant time after O(nm) preprocessing.
Prefix Sum and Difference Array
Prefix sums precompute running totals so any range sum [l, r] can be answered in O(1) time as prefix[r] - prefix[l-1].
Sorting Algorithms
Sorting arranges items into a chosen order so that searching, grouping, and further algorithms become faster and simpler.
Greedy Algorithms
Greedy algorithms build a solution step by step by always taking the best local choice available.
Ternary Search
Ternary search finds the maximum or minimum of a unimodal function on a line by probing two interior points and discarding one third of the interval each step.
Binary Search
Binary search quickly finds targets or boundaries in sorted or monotonic data by halving the search interval each step.