What is the difference between a heap (a minheap) and a binary search tree?

Print "usernum1 is negative." if usernum1 is less than 0. end with newline. convert usernum2 to 0 if usernum2 is greater than 10. otherwise, print "usernum2 is less than or equal to 10.". end with newline

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?

Need fast im timed in a paragraph of 125 words, explain at least three ways that engineers explore possible solutions in their projects.