<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>

from collections import defaultdict

class Solution:
    def invalidTransactions(self, transactions: List[str]) -> List[str]:
        customers = defaultdict(list)
        res = []
        for transaction in transactions:
            name, time, amt, city = transaction.split(',')
            customers[name].append((time, amt, city))
        for customer_name in customers.keys():
            ts = sorted(customers[customer_name])
            for i in range(0,len(ts)):
                time = int(ts[i][0])
                amt = int(ts[i][1])
                city = ts[i][2]
                added = False
                for j in range(0,len(ts)):
                    if i != j:
                        time2 = int(ts[j][0])
                        amt2 = int(ts[j][1])
                        city2 = ts[j][2]
                        if i > 0 and city2 != city and abs(time2 - time) <= 60:
                            res.append(customer_name + ',' + ','.join(ts[i]))
                            added = True
                            break
                        elif i < len(ts) - 1 and city2 != city and abs(time2 - time) <= 60:
                            res.append(customer_name + ',' + ','.join(ts[i]))
                            added = True
                            break
                if not added and amt > 1000:
                    res.append(customer_name + ',' + ','.join(ts[i]) )     
        return res
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