Time Complexity: O(N)

#include <bits/stdc++.h> 
int largestElement(vector<int> &arr, int n) {
    // Write your code here.
    int maxi = INT_MIN;
    for(int i=0;i<n;i++){
        if(arr[i]>maxi)
            maxi = arr[i];
    }
    return maxi;
}

vector<int> countFrequency(int n, int x, vector<int> &nums){
    // Write your code here.
    vector<int> ans(n);
    for(int i=0;i<nums.size();i++){
        ans[nums[i]-1]++;
    }
    return ans;
}

long long fact(long long x){
    if(x==1) return 1;
    return x*fact(x-1);
}

vector<long long> factorialNumbers(long long n) {
    // Write Your Code Here
    vector<long long> ans;
    long long x;
    for(long long i=1;i<=n;i++){
        x=fact(i);
        if(x>n)
            return ans;
        else
            ans.push_back(x);
    }
}