struct_assignments.sol

// SPDX-License-Identifier: MIT
pragma solidity 0.8.9;

contract StorageToStorage {
  struct Transcoder {
    uint256 cumulativeRewards;
    uint256 cumulativeFees;
  }

  mapping(address => Transcoder) public transcoders;
  
  Transcoder public s;

  function setTranscoder(address a, uint256 r, uint256 f) public{
    Transcoder memory t;
    t.cumulativeFees = f;
    t.cumulativeRewards = r;
    transcoders[a] = t;
  }
  
  function clearTranscoder(address a) public{
    Transcoder storage t = transcoders[a];
    t.cumulativeFees = 0;
    t.cumulativeRewards = 0;
  }

  function setS(uint256 r, uint256 f) public{
    Transcoder memory t;
    t.cumulativeFees = f;
    t.cumulativeRewards = r;
    s = t;
  }

  function clearS() public {
    Transcoder storage t = s;
    t.cumulativeFees = 0;
    t.cumulativeRewards = 0;
  }
}