UNIT - 5 DECREASE-AND-CONQUER APPROACHES, SPACE-TIME TRADEOFFS: Decrease-and-Conquer Approaches: Introduction, Insertion Sort, Depth First Search and Breadth First Search, Topological Sorting Space-Time Tradeoffs: Introduction Enhancement in String Matching(Horspools String matching). UNIT – 6 LIMITATIONS OF ALGORITHMIC POWER AND COPING WITH THEM: Decision Trees, P, NP, and NP-Complete Problems UNIT - 7 COPING WITH LIMITATIONS OF ALGORITHMIC POWER: Backtracking: n - Queens problem Subset –Sum Problem. Approximation algorithms for Traveling Salesman Problem(TSP): i. Nearest-Neighbor algorithm ii. Twice-around-the –tree algorithm