What would be the practical effects if it is proved that P=NP and an efficient polynomial time algorithm is found for NP-complete problems? By practical effects, I mean the practical effects of perfectly solving the problems which have been proven to be NP-complete (like Boolean SAT, Traveling salesman, scheduling, etc.)? Because from what I have gathered, approximate algorithms (like stochastic alogrithms for e.g.) are pretty good at finding answers close to the perfect answers and algorithms that do find perfect answers if given enough time find it in reasonable times for most cases. So will there be significant practical effects if P=NP (aside from the fact that cryptography will become impossible)?