EASY C++ 100% O(1)
Complexity
Time complexity:O(1)
Aux. Space:O(1)
Code

# Complexity
- Time complexity: $$O(1)$$ 
- Aux. Space: $$O(1)$$ 

# Code
```cpp []
class Solution {
public:
    bool isRectangleOverlap(vector<int>& rec1, vector<int>& rec2) {
        return rec1[0] < rec2[2] 
            && rec2[0] < rec1[2] 
            && rec1[1] < rec2[3] 
            && rec2[1] < rec1[3];
    }
};
```
['Math', 'Geometry', 'C++']