Cs6515 algorithms - Study guides, Class notes & Summaries

How do you tell if a graph has negative edges? - ANSWER-when fitting graph on a table, if the number of moves decreases the w() from edge to edge, then there is a negative edge; check from 1 to n Why are all pairs Dist(y,z) n^2? - ANSWER-Because it builds a two dim table! What is the run time of bellman ford algorithm? How about if you had to do it for all edges? - ANSWER-O(nm) O(n^2m) Floyd-Warshall run time? - ANSWER-O(n^3) What is the base case for the bellman ford algorithm? - ANSWE...

Steps to solve a Dynamic Programming Problem - ANSWER-1. Define the Input and Output. 2. Define entries in table, i.e. T(i) or T(i, j) is... 3. Define a Recurrence relationship - Based on a subproblem to the main problem. (hint: use a prefix of the original input 1 < i < n). 4. Define the Pseudocode. 5. Define the Runtime of the algorithm. Use Time Function notation here => T(n) = T(n/2) + 1... DP: Types of Subproblems (4) - ANSWER-Input = x1, x2, ..., xn 1) Subproblem = x1, x2...

DFS outputs - ANSWER-pre array, post array, ccnum array, prev array BFS outputs - ANSWER-dist array, prev array Explore outputs - ANSWER-visited array. When to use Dijkstra's? - ANSWER-Works for both directed and undirected graphs. Must have only non-negative edge weights. Dijkstra's outputs - ANSWER-dist array, prev array Dijkstra's runtime? - ANSWER-O((n+m) log n) log n is from using the min heap (to get the lowest cost weight) When to use Bellman Ford? - ANSWER-Use when there is a ...