Let's say we are given an array:
[4,1,5,2,3,0,10]
We want to get K = 3 smallest items from the array and using Max heap data structure.
So this is how to think about it.
1. We take first K items put it into Max Heap:
5
/
4 1
2. Then we move forward to next element '2' in the array, we check
- Whether 2 is smaller than current max item in heap, which is '5', if yes, then replace 5 with 2
- Then re-arrange the heap
4
/
2 1
3. Repeat the process for items [3,0]
3 2
/ /
2 1 0 1
4. When the item is '10' which is larger than current max '2', we just ingore it.
5. In the end, we got K smallest items, we just need to print it out. (K smallest items are not ncessary in order)