Here are two examples of Solidity contracts.
This is the ink! flipper example written in Solidity:
A few simple arithmetic functions.
There is an example on Solana's integration tests for a Solidity contract that manages an NFT. The contract is supposed to be the NFT itself. It can mint itself and transfer ownership. It also stores on chain information about itself, such as its URI. Please, check simple_collectible.sol for the Solidity contract and simple_collectible.spec.ts for the Typescript code that interacts with Solidity.
On Solana, it is possible to create a hash table on chain with program derived addresses (PDA). This is done by using the intended key as the seed for finding the PDA. There is an example of how one can achieve so in our integration tests. Please, check UserStats.sol for the Solidity contract and user_stats.spec.ts for the client code, which contains most of the explanations about how the table works. This example was inspired by Anchor's PDA hash table.