Solution for Summer of Bitcoin Code Challenge

problem statement

Given an pool of transactions which consists of

• tx_id of that transaction
• fee to the miner
• weight of the transaction
• parents which consists of list of parent tx_ids

select the transactions that gives the maximum possible fee to the miner
such that total weight of a transaction doesn't exceed maximum limit = 4,000,000
and the order in which tx_ids should apper after their parent_ids are appered

My Solution Approach:

• Take the input from csv file and convert that data into python data structures
• I have choosen dictionary to hold the enter data and a list of tx_ids which is used for sorting based on the condition
• Dictionary holds the key as tx_id and value as dictionary of fee,weight,parents, which looks something like below

  data =
         { "tx_id" :
            {
                 "fee" :<int-value> ,
                      "weight" : <int-value>,
                      "parents" : list of parent tx_ids
             }
          }

• Greedily select those tx_ids which gives maximum fee with minimum weight
• Sort the tx_id list based on the above condition
• While taking a tx_id, along with it's fee parent tx_id fee and weight are also added and parent tx_id should be placed before child tx_ids
• So stack like data structure is used to push parent tx_ids into final answer before child tx_id

for running the project

• Enter a file name (default = mempool.csv)
• python main.py
• clear the block.txt file if present already