Real-world example of exponential time complexity

Question

I\'m looking for an intuitive, real-world example of a problem that takes (worst case) exponential time complexity to solve for a talk I am giving.

Here are examples for

Answer 1

• O(10^N): trying to break a password by testing every possible combination (assuming numerical password of length N)

p.s. why is your last example is of complexity O(infinity) ? it's linear search O(N) .. there are less than 7 billion people in the world.