What is a loop invariant?
I'm reading "Introduction to Algorithm" by CLRS. In chapter 2, the authors mention "loop invariants". What is a loop invariant? Tomas Petricek In simple words, a loop invariant is some predicate (condition) that holds for every iteration of the loop. For example, let's look at a simple for loop that looks like this: int j = 9; for(int i=0; i<10; i++) j--; In this example it is true (for every iteration) that i + j == 9 . A weaker invariant that is also true is that i >= 0 && i <= 10 . TNi I like this very simple definition: ( source ) A loop invariant is a condition [among program variables]