Han Zhu's Study Notes

Given a stream of integers and a window size, calculate the moving average of all integers in the sliding window. For example, MovingAverage m = new MovingAverage(3); m.next(1) = 1 m.next(10) = (1 + 10) / 2 m.next(3) = (1 + 10 + 3) / 3 m.next(5) = (10 + 3 + 5) / 3 Thought process: Use queue. Solution: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 class MovingAverage { private double sum ; private int capacity ; private Queue < Integer > queue ; /** Initialize your data structure here. */ public MovingAverage ( int size ) { capacity = size ; sum = 0 ; queue = new LinkedList <>(); } public double next ( int val ) { if ( queue . size () == capacity ) { sum -= queue . poll (); } queue . offer ( val ); sum += val ; return sum / queue . size (); } } /** * Your MovingAvera...

Given a char array representing tasks CPU need to do. It contains capital letters A to Z where different letters represent different tasks.Tasks could be done without original order. Each task could be done in one interval. For each interval, CPU could finish one task or just be idle. However, there is a non-negative cooling interval  n  that means between two  same tasks , there must be at least n intervals that CPU are doing different tasks or just be idle. You need to return the  least  number of intervals the CPU will take to finish all the given tasks. Example 1: Input: tasks = ['A','A','A','B','B','B'], n = 2 Output: 8 Explanation: A -> B -> idle -> A -> B -> idle -> A -> B. Note: The number of tasks is in the range [1, 10000]. The integer n is in the range [0, 100]. Thought process: The tasks with higher numbers of instances should be executed before the ones with lower numbers of insta...