<p>Given an array <code>intervals</code> where <code>intervals[i] = [l<sub>i</sub>, r<sub>i</sub>]</code> represent the interval <code>[l<sub>i</sub>, r<sub>i</sub>)</code>, remove all intervals that are covered by another interval in the list.</p>

<p>The interval <code>[a, b)</code> is covered by the interval <code>[c, d)</code> if and only if <code>c &lt;= a</code> and <code>b &lt;= d</code>.</p>

<p>Return <em>the number of remaining intervals</em>.</p>

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

<pre>
<strong>Input:</strong> intervals = [[1,4],[3,6],[2,8]]
<strong>Output:</strong> 2
<strong>Explanation:</strong> Interval [3,6] is covered by [2,8], therefore it is removed.
</pre>

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

<pre>
<strong>Input:</strong> intervals = [[1,4],[2,3]]
<strong>Output:</strong> 1
</pre>

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

<ul>
	<li><code>1 &lt;= intervals.length &lt;= 1000</code></li>
	<li><code>intervals[i].length == 2</code></li>
	<li><code>0 &lt;= l<sub>i</sub> &lt; r<sub>i</sub> &lt;= 10<sup>5</sup></code></li>
	<li>All the given intervals are <strong>unique</strong>.</li>
</ul>

class Solution {
public:
    int removeCoveredIntervals(vector<vector<int>>& intervals) {
        sort(intervals.begin(), intervals.end());
        stack<vector<int>> st;
        st.push(intervals[0]);
        for(int i=1;i<intervals.size();i++){
            vector<int> temp = st.top();
            st.pop();
            if (temp[0]<=intervals[i][0] and temp[1]>=intervals[i][1]){
                st.push(temp);
            }
            else if(temp[0]==intervals[i][0] and temp[1]<intervals[i][1]){
                st.push(intervals[i]);
            }
            else{
                st.push(temp);
                st.push(intervals[i]);
            }
        }

        return st.size();

    }
};


// intervals.sort()
//         # ans=0
//         stack=[]
//         stack.append(intervals[0])
//         for i in range(1,len(intervals)):
//             # print(stack)
//             temp = stack.pop()
//             # print("temp[0] - ", temp[0],"temp[1] - ",temp[1],"intervals[i][0] - ",intervals[i][0],"intervals[i][1] - ",intervals[i][1])
//             if (temp[0]<=intervals[i][0] and temp[1]>=intervals[i][1]):
//                 # ans+=1
//                 stack.append(temp)
//             elif (temp[0]==intervals[i][0] and temp[1]<intervals[i][1]):
//                 stack.append(intervals[i]) #beware of this usecase free good
//             else:
//                 stack.append(temp)
//                 stack.append(intervals[i])
        
            
//         # print(intervals)
//         return len(stack)
16600