Formatted question description: https://leetcode.ca/all/1313.html

# 1313. Decompress Run-Length Encoded List (Easy)

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 .
The second pair [3,4] means we have freq = 3 and val = 4 so we generate [4,4,4].
At the end the concatenation  + [4,4,4,4] is [2,4,4,4].


Constraints:

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

Related Topics:
Array

Similar Questions:

## Solution 1.

// OJ: https://leetcode.com/problems/decompress-run-length-encoded-list/

// Time: O(N) where N is the length of the output array.
// Space: O(1)
class Solution {
public:
vector<int> decompressRLElist(vector<int>& nums) {
vector<int> ans;
for (int i = 0; i < nums.size(); i += 2) {
for (int j = 0; j < nums[i]; ++j) ans.push_back(nums[i + 1]);
}
return ans;
}
};


Java

class Solution {
public int[] decompressRLElist(int[] nums) {
List<Integer> list = new ArrayList<Integer>();
int length = nums.length;
for (int i = 0; i < length; i += 2) {
int count = nums[i];
int value = nums[i + 1];
for (int j = 0; j < count; j++)