Prisoner's Dilemma Algorithm

Since there is only one choice to make, and in the absence of any changeable inputs, your algorithm is either going to be:

cooperate = true;

...or...

cooperate = false

It's more interesting to find a strategy for the Iterated Prisoner's Dilemma, which is something many people have done. For example http://www.iterated-prisoners-dilemma.info/

Even then it's not 'solvable' since the other player is not predictable.

The wikipedia page seems to give all the answers... for the one-time prisoner's dilemma, the most optimal solution for each prisoner (not both prisoners) is to betray.

For the iterated prisoner's dilemma, it is best to remain silent on the first go, and then after that do whatever the other prisoner did on the last go.

The whole point of the dilemma is that the optimal solution (both prisoners stay quiet) is dangerous because part of the problem is out of your hands. So, choosing the suboptimal solution seems to maximize your gain, but it's still suboptimal

I don't see how an algorithm could supply a solution when part of the problem is the unknown.