---
tags: leetcode
---

# [253. Meeting Rooms II](https://leetcode.com/problems/meeting-rooms-ii/)
---
# My Solution
## The Key Idea for Solving This Coding Question
## C++ Code

#define START (0)
#define END (1)

class cmp {
public:
    bool operator()(int a, int b) {
        return a > b;
    }
};

class Solution {
public:
    int minMeetingRooms(vector<vector<int>> &intervals) {
        sort(intervals.begin(), intervals.end(), 
             [](vector<int> &a, vector<int> &b){ return a[START] < b[START]; });

        int rooms = 0;
        priority_queue<int, vector<int>, cmp> heap;
        for (auto &interval : intervals) {
            while (!heap.empty() && interval[START] >= heap.top()) {
                heap.pop();
            }
            heap.push(interval[END]);

            if (rooms < heap.size()) {
                rooms = heap.size();
            }
        }

        return rooms;
    }
};

## Time Complexity
## Space Complexity
# Miscellaneous
<!--
# Test Cases

[[0,30],[5,10],[15,20]]

[[7,10],[2,4]]

* Wrong Answer:

[[13,15],[1,13]]

* Wrong Answer:

[[9,10],[4,9],[4,17]]

* Wrong Answer:

[[5,8],[6,8]]

* Wrong Answer:

[[13,15],[1,13],[6,9]]

-->