It would require a fairly complex thermo-fluid calculations.
As per said in other answers it is not correct that you need 4 cylinder engine for the turbo charger to work as i have seen turbo working in even single cylinder engines too.Its just that it requires precise assumptions and calculations.
Also, its is not mandatory to use intercooler with turbo charger as it depends on the compression ratio of turbo which further depends on the geometry of the compression turbine, exhaust gas pressure and designing of ducts which carry compressed air from turbo to intake manifold. So again you need to dig a little deeper into thermo-fluidic concepts.
I think what major challenge you will face is the availablity/designing challenges of such a small turbo charger to initiate compression at the exhaust pressure of the 100cc engine, provide enough compression to not to increase the intake pressure at cylinder upto the extent that it would not cause damage to the engine. Damages that are possible due to very high intake/turbo boost pressure may include increase in blow by, damage to engine block, piston rings and valves as these things are designed for a specific cylinder pressure which you will increase by adding turbo.
Also there would be a challenge to design the ducts for the system.