Difference among Uniswap V1, V2, V3, V4

## Summary
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Uniswap has evolved through various versions, from V1 to V4. Notably, the protocol introduced concentrated liquidity in Uniswap V3. Furthermore, the Uniswap V4 contract has been locked, indicating that there will be no major changes to the protocol's codebase. Once the testing phase is completed, it will be deployed on the mainnet. Please research the differences and similarities among the different versions of Uniswap and provide insights into the evolution and improvements of the protocol over time.

## Description
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Concentrated Liquidity is introduced in the Uniswap V3 protocol, different from the approach of storing token balances as seen in Uniswap V2. Instead, Uniswap V3 utilizes price and liquidity in its calculations. What challenges did Uniswap V2 face, and how does Uniswap V3 resolve them? Extensive research into both the concept and the codebase implementation is necessary. Furthermore, what current challenges does Uniswap V3 encounter, and does Uniswap V4 offer potential solutions to these challenges? If Uniswap V4 is released, how does it attempt to address these challenges?

## Source
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[Uniswap V3 Book](https://uniswapv3book.com/)

[Uniswap V4](https://docs.uniswap.org/contracts/v4/concepts/intro-to-v4)

[窺探 UniswapV4 的核心機制](https://medium.com/taipei-ethereum-meetup/exploring-the-core-mechanisms-of-uniswap-v4-83a491fdf6be)

## Others
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None