//SPDX-License-Identifier: UNLICENSED"
pragma solidity ^0.8.1;

interface IUniswapV2Factory {
    function allPairs(uint256) external view returns (address pair);

    function allPairsLength() external view returns (uint256);
}

contract PairAddressesChecker {
    receive() external payable {
        revert("PairAddressChecker does not accept payments");
    }
    
    function getPairsAddressesLength(address factory)
        external
        view
        returns (uint256)
    {
        uint256 length = IUniswapV2Factory(factory).allPairsLength();

        return length;
    }

    function getPairsAddresses(address factory, uint256 start, uint256 end)
        external
        view
        returns (address[] memory)
    {
        uint256 length = IUniswapV2Factory(factory).allPairsLength();
        require(start<end, "Start index must be smaller than End index");
        if(end<length)
            length= end;
        require(start<length, "Start index must be smaller than Pairs Array length");
        address[] memory pairsAddresses = new address[](length-start);
        for (uint256 i = start; i < length; i++) {
            pairsAddresses[i-start] = IUniswapV2Factory(factory).allPairs(i);
        }

        return pairsAddresses;
    }
}