class Solution {
public:
vector<int> decompressRLElist(vector<int>& nums) {
vector<int> ans;
int N = nums.size();
for(int i=0;i<N;i+=2){
for(int j=0;j<nums[i];j++){
ans.push_back(nums[i+1]);
}
}
return ans;
}
};