<p>A transaction is possibly invalid if:</p>

<ul>
	<li>the amount exceeds <code>$1000</code>, or;</li>
	<li>if it occurs within (and including) <code>60</code> minutes of another transaction with the <strong>same name</strong> in a <strong>different city</strong>.</li>
</ul>

<p>You are given an array of strings <code>transaction</code> where <code>transactions[i]</code> consists of comma-separated values representing the name, time (in minutes), amount, and city of the transaction.</p>

<p>Return a list of <code>transactions</code> that are possibly invalid. You may return the answer in <strong>any order</strong>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> transactions = [&quot;alice,20,800,mtv&quot;,&quot;alice,50,100,beijing&quot;]
<strong>Output:</strong> [&quot;alice,20,800,mtv&quot;,&quot;alice,50,100,beijing&quot;]
<strong>Explanation:</strong> The first transaction is invalid because the second transaction occurs within a difference of 60 minutes, have the same name and is in a different city. Similarly the second one is invalid too.</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> transactions = [&quot;alice,20,800,mtv&quot;,&quot;alice,50,1200,mtv&quot;]
<strong>Output:</strong> [&quot;alice,50,1200,mtv&quot;]
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> transactions = [&quot;alice,20,800,mtv&quot;,&quot;bob,50,1200,mtv&quot;]
<strong>Output:</strong> [&quot;bob,50,1200,mtv&quot;]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>transactions.length &lt;= 1000</code></li>
	<li>Each <code>transactions[i]</code> takes the form <code>&quot;{name},{time},{amount},{city}&quot;</code></li>
	<li>Each <code>{name}</code> and <code>{city}</code> consist of lowercase English letters, and have lengths between <code>1</code> and <code>10</code>.</li>
	<li>Each <code>{time}</code> consist of digits, and represent an integer between <code>0</code> and <code>1000</code>.</li>
	<li>Each <code>{amount}</code> consist of digits, and represent an integer between <code>0</code> and <code>2000</code>.</li>
</ul>

'''
sort transaction by time
dict (defaultdict(list)) = name:(city1, time),(city2, time(most recent))
for each transaction:
    if name in dict:
        if most recent city != current_city and current_time -time <=60":
            add city and current_city into invalid
        add current_city into dict
    elif transaction > 1000:
        add current_city into invalid
    add transaction dict
'''
class Solution:
    def invalidTransactions(self, transactions: List[str]) -> List[str]:
        travelDict = defaultdict(list)
        invalidset = set()
        sorted_transactions = transactions.copy()
        for i in range(len(sorted_transactions)):
            tl = sorted_transactions[i].split(",")
            sorted_transactions[i] = (tl[0], int(tl[1]), int(tl[2]), tl[3], i)
        sorted_transactions = sorted(sorted_transactions, key=lambda a:a[1])
        
        for transaction in sorted_transactions:
            new_name, new_time, new_amount, new_city, index = transaction
            if new_name in travelDict:
                for old_transaction in reversed(travelDict[new_name]):
                    _, old_time, _, old_city, old_index = old_transaction
                    print(old_time, old_city)
                    if old_city != new_city and new_time - old_time <= 60:
                        invalidset.add(index)
                        invalidset.add(old_index)      
            if new_amount > 1000:
                invalidset.add(index)
            travelDict[new_name].append(transaction)
        return [transactions[x] for x in invalidset]
184