# excercise example found on CodeSignal

def solution(queries):
    ret_list = []  # output
    work_dict = {} # ledger-like, use accountid as hash for key, and for val use (id,balance) list
    act_dict = {}

    for l in queries:
        operation, timestamp, account_id = l[0], l[1], l[2]

        if operation == 'CREATE_ACCOUNT':
            if work_dict.get(account_id) is not None:
                ret_list.append("false") # account already present
            else:
                work_dict[account_id] = [account_id, 0]  # add id,balance list to dict
                ret_list.append("true")
                act_dict[account_id] = 0

        elif operation == "DEPOSIT":
            if work_dict.get(account_id) is None:
                ret_list.append("")
            else:
                current_balance = work_dict[account_id][1]
                work_dict[account_id][1] = current_balance + int(l[3])
                ret_list.append(str(work_dict[account_id][1]))

                act_dict[account_id] += int(l[3])

        elif operation == "PAY":
            if work_dict.get(account_id) is None:
                ret_list.append("")
            else:
                current_balance = work_dict[account_id][1]
                if current_balance >= int(l[3]):
                    work_dict[account_id][1] = current_balance - int(l[3])
                    ret_list.append(str(work_dict[account_id][1]))
                    
                    act_dict[account_id] += int(l[3])
                else:
                    ret_list.append("")

        elif operation == "TOP_ACTIVITY":
            n = int(l[2]) # top n accounts
            top_string = ""
            for w in sorted(act_dict, key=act_dict.get, reverse=True)[:n]:
                top_string += f"{str(w)}({act_dict[w]}), "
            ret_list.append(top_string[:-2])

    return ret_list


q = [["CREATE_ACCOUNT","1","account1"], 
 ["CREATE_ACCOUNT","2","account2"], 
 ["CREATE_ACCOUNT","3","account3"], 
 ["DEPOSIT","4","account1","1000"], 
 ["DEPOSIT","5","account2","1000"], 
 ["DEPOSIT","6","account3","1000"], 
 ["PAY","7","account2","100"], 
 ["PAY","8","account2","100"], 
 ["PAY","9","account3","100"], 
 ["TOP_ACTIVITY","10","3"]]

print(solution(q))

'''Expected Output:

["true", 
 "true", 
 "true", 
 "1000", 
 "1000", 
 "1000", 
 "900", 
 "800", 
 "900", 
 "account2(1200), account3(1100), account1(1000)"]
'''


'''Warmup excercise:

given following list of lists:
queries = [
    ["ADD", "1"],
    ["ADD", "2"],
    ["ADD", "5"],
    ["ADD", "2"],
    ["EXISTS", "2"],
    ["EXISTS", "5"],
    ["EXISTS", "1"],
    ["EXISTS", "4"],
    ["EXISTS", "3"],
    ["EXISTS", "0"]
]

that will be passed into following function that will be called once:
def solution(queries):

what code can produces following output:
["", "", "", "", "true", "true", "true", "false", "false", "false"]

My solution:
def solution(queries):
    mylist = []
    ret = []
    for l in queries:
        if l[0] == 'ADD':
            mylist.append(l[1])
            ret.append("")
        elif l[0] == 'EXISTS':
            if l[1] in mylist:
                ret.append("true")
            else:
                ret.append("false")
    return ret%                           
    
'''