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[2*i], nums[2*i+1]] (with i >= 0). For each such pair, there are a elements with value b in the decompressed list.

Return the decompressed list.

Example 1:

Input: nums = [1,2,3,4]
Output: [2,4,4,4]
Explanation: The first pair [1,2] means we have freq = 1 and val = 2 so we generate the array [2].
The second pair [3,4] means we have freq = 3 and val = 4 so we generate [4,4,4].
At the end the concatenation [2] + [4,4,4,4] is [2,4,4,4].

Constraints:

2 <= nums.length <= 100
nums.length % 2 == 0
1 <= nums[i] <= 100

class Solution {
    public int[] decompressRLElist(int[] nums) {
        List<Integer> list = new ArrayList<>();
        for (int i = 0; i < nums.length; i += 2) {
            for (int j = 0; j < nums[i]; j++) {
                list.add(nums[i + 1]);
            }
        }
        int[] res = new int[list.size()];
        for (int i = 0; i < list.size(); i++) {
            res[i] = list.get(i);
        }
        return res;
    }
}

https://leetcode.com/problems/decompress-run-length-encoded-list/discuss/478859/Simple-Java-Solution

我宣布，这是2020leetcode第一粪题，描述的跟屎一样