题解 | #滑动窗口的最大值#

import java.util.*;
public class Solution {
    public ArrayList<Integer> maxInWindows(int [] num, int size) {
        
        ArrayList<Integer> arrayList = new ArrayList<>();
        int numL = num.length;
        
        // 一些特殊情况的处理
        if (numL < size || 0 == size) {
            return arrayList;
        }
        
        int start = 0;
        int end = size - 1;
        
        // 初始化
        int[] maxIndexAndValue = new int[2];
        int maxIndex = -1;
        int maxValue = Integer.MIN_VALUE;
        
        while (end < numL) {
            if (!(start <= maxIndex && maxIndex <= end)) {
                maxIndexAndValue = FindMax(num, start, end);
                maxIndex = maxIndexAndValue[0];
                maxValue = maxIndexAndValue[1];
                arrayList.add(maxValue);
                start++;
                end++;
            }
            else {
                if (num[end] >= maxValue) {
                    maxValue = num[end];
                    maxIndex = end;
                    arrayList.add(maxValue);
                    start++;
                    end++;
                }
                else {
                    arrayList.add(maxValue);
                    start++;
                    end++;
                }
            }
        }
        
        return arrayList;
    }
    
    public int[] FindMax(int[] num, int start, int end) {
        int[] maxIndexAndValue = new int[2];
        int maxIndex = 0;
        int maxValue = Integer.MIN_VALUE;
        
        for (int i = start; i <= end; i++) {
            if (num[i] > maxValue) {
                maxValue = num[i];
                maxIndex = i;
            }
        }
        maxIndexAndValue[0] = maxIndex;
        maxIndexAndValue[1] = maxValue;
        return maxIndexAndValue;
    }
}