<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>

class Solution {
    struct Data {
        string name;
        int time;
        int amount;
        string city;
    };
    
    Data getToken(string &s) {
        Data curr;
        string str;
        for (int i = 0, j = 0; i < s.length(); ++i) {
            if (s[i] == ',') {
                if (j == 0)
                    curr.name = str;
                else if (j == 1)
                    curr.time = getNum(str);
                else
                    curr.amount = getNum(str);
                ++j;
                str = "";
            } else
                str += s[i];
        }
        
        curr.city = str;
        return curr;
    }
    
    int getNum(string &s) {
        int res = 0;
        
        for (auto c: s)
            res = res*10 + c - '0';
        
        return res;
    }
    
public:
    vector<string> invalidTransactions(vector<string>& transactions) {
        vector<string> res;
        unordered_map<string, vector<int>> lut;
        unordered_map<int, Data> lut2;
        
        vector<int> visited(transactions.size(), 0);
        for (int i = 0; i < transactions.size(); ++i) {
            Data curr = getToken(transactions[i]);
            
            if (curr.amount > 1000) {
                res.push_back(transactions[i]);
                visited[i] = 1;
            }
            
            lut[curr.name].push_back(i);
            lut2[i] = curr;
        }
        
        for (auto &[name, v]: lut) {
            sort(v.begin(), v.end(),
                 [&](int i, int j) {
                     return lut2[i].time < lut2[j].time;
                });
            
            if (name == "chalicefy") {
                cout << "[";
                for (auto i: v)
                    cout <<'"'<< transactions[i] <<'"'<<",";
                cout <<"]"<< endl;
            }
            
            int l = 0;
            for (int r = 1; r < v.size(); ++r) {
                int curr = v[r];
                while (l < r) {
                    int t = v[l];
                    if (lut2[t].time + 60 < lut2[curr].time)
                        ++l;
                    else {
                        for (int j = l; j < r; ++j) {
                            if (lut2[v[j]].city != lut2[curr].city) {
                                if (visited[v[j]] == 0) {
                                    visited[v[j]] = 1;
                                    res.push_back(transactions[v[j]]);
                                }
                                if (visited[curr] == 0) {
                                    visited[curr] = 1;
                                    res.push_back(transactions[curr]);
                                }
                            }
                        }
                        break;
                    }
                }
            }
        }
        
        return res;
    }
};
16400