附leetcode链接：https://leetcode.com/problems/decompress-run-length-encoded-list/
1313. Decompress Run-Length Encoded List
We are given a list nums of integers representing a list compressed with run-length encoding.
Consider each adjacent pair of elements [a,b] = [nums[2i],nums[2i+1]](with i >= 0).For each such pair, there are a elements with value b in the decompressed list.

public int[] decompressRLElist(int[] nums) {
        ArrayList<Integer> a = new ArrayList<Integer>();
        int t = 0;
        for(int i = 0;i<nums.length;i = i + 2) {
              for(int j = 0;j<nums[i];j++){
                      a.add(nums[i+1]);
              }  
        }
        int b[] = new int[a.size()];
        for (int i = 0; i < a.size();i++) {
              b[i] = a.get(i);
        }
        return b;
}

小结:当前解法不是最快的，有待进一步探索；
属于对【整形数组】的处理；
用到了双重循环；
数组初始化的时候必须指定长度，这里用到了ArrayList，长度动态分配；
用一个for循环转换成普通的数组；
list常用的add、get、size方法：https://www.runoob.com/java/java-collections.html；